National Library of Energy BETA

Sample records for direction uni-directional simulated

  1. Variable mode bi-directional and uni-directional computer communication system

    DOE Patents [OSTI]

    Cornett, Frank N.; Jenkins, Philip N.; Bowman, Terrance L.; Placek, Joseph M.; Thorson, Gregory M.

    2004-12-14

    A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.

  2. Forward-Only Uni-Directional Routing Jorge A. Cobb

    E-Print Network [OSTI]

    Cobb, Jorge Arturo

    , such as limits on battery life, memory, and computing power. Battery life is critical, since nodes are typically battery operated, and have a short battery life. To maximimize battery life, an efficient utilization has a set of network conditions under which it is the best. In this paper, we focus on the proactive

  3. Distributed sensing, damage detection and analysis in FRP uni-directional Patrick Rye; Graduate Student; University of California, San Diego;

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    ; Graduate Student; University of California, San Diego; 9450 Giman Drive 0416, La Jolla, CA 92093-0416 Yi Huang; Graduate Student; University of California, San Diego; 9450 Giman Drive 0416, La Jolla, CA 92093-0416 Fabrizia Ghezzo; Post-doctorial Researcher; University of California, San Diego; 9450 Giman Drive 0416, La

  4. Sandia Energy - Direct Numerical Simulation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumniProjectsCyberNot Chemistry Diamond PlatesDirect

  5. Direct numerical simulation of turbulent reacting flows

    SciTech Connect (OSTI)

    Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

  6. Direct numerical simulations of aeolian sand ripples

    E-Print Network [OSTI]

    Orencio Duran; Philippe Claudin; Bruno Andreotti

    2014-11-07

    Aeolian sand beds exhibit regular patterns of ripples resulting from the interaction between topography and sediment transport. Their characteristics have been so far related to reptation transport caused by the impacts on the ground of grains entrained by the wind into saltation. By means of direct numerical simulations of grains interacting with a wind flow, we show that the instability turns out to be driven by resonant grain trajectories, whose length is close to a ripple wavelength and whose splash leads to a mass displacement towards the ripple crests. The pattern selection results from a compromise between this destabilizing mechanism and a diffusive downslope transport which stabilizes small wavelengths. The initial wavelength is set by the ratio of the sediment flux and the erosion/deposition rate, a ratio which increases linearly with the wind velocity. We show that this scaling law, in agreement with experiments, originates from an interfacial layer separating the saltation zone from the static sand bed, where momentum transfers are dominated by mid-air collisions. Finally, we provide quantitative support for the use the propagation of these ripples as a proxy for remote measurements of sediment transport.

  7. Direct Numerical Simulation of the Flow in a Pebble Bed 

    E-Print Network [OSTI]

    Ward, Paul

    2014-06-24

    at Argonne National Laboratory, to conduct both large eddy simulation (LES) and direct numerical simulation (DNS) of fluid flow through a single face-centered cubic sphere lattice with periodic boundary conditions. Multiple LES were conducted with varying...

  8. Direct Numerical Simulations and Robust Predictions of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name:...

  9. Future Directions in Simulating Solar Geoengineering

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.; Robock, Alan; Boucher, Olivier

    2014-08-05

    Solar geoengineering is a proposed set of technologies to temporarily alleviate some of the consequences of anthropogenic greenhouse gas emissions. The Geoengineering Model Intercomparison Project (GeoMIP) created a framework of geoengineering simulations in climate models that have been performed by modeling centers throughout the world (B. Kravitz et al., The Geoengineering Model Intercomparison Project (GeoMIP), Atmospheric Science Letters, 12(2), 162-167, doi:10.1002/asl.316, 2011). These experiments use state-of-the-art climate models to simulate solar geoengineering via uniform solar reduction, creation of stratospheric sulfate aerosol layers, or injecting sea spray into the marine boundary layer. GeoMIP has been quite successful in its mission of revealing robust features and key uncertainties of the modeled effects of solar geoengineering.

  10. A goal directed simulation method using fuzzy cognitive mapping 

    E-Print Network [OSTI]

    Deines, Erich Vernon

    1996-01-01

    A goal directed simulation method using fuzzy cognitive mapping (FCM-GDS) is partially developed. The FCM-GDS system can be used for the analysis and experimental design associated with traditional manufacturing studies. The FCM-GDS system...

  11. 38 CHAPTER 1. ASSEMBLY MANUAL BiDirectional Motor

    E-Print Network [OSTI]

    38 CHAPTER 1. ASSEMBLY MANUAL Bi­Directional Motor and Infrared Beacon Uni­Directional Motor, LED to build reliable cables and connectors for the motors and sensors that will plug into the robot more reliable overall and will ease development difficulties. Sensors and motors are built

  12. A fast direct numerical simulation method for characterising hydraulic roughness

    E-Print Network [OSTI]

    Chung, Daniel; MacDonald, Michael; Hutchins, Nicholas; Ooi, Andrew

    2015-01-01

    We describe a fast direct numerical simulation (DNS) method that promises to directly characterise the hydraulic roughness of any given rough surface, from the hydraulically smooth to the fully rough regime. The method circumvents the unfavourable computational cost associated with simulating high-Reynolds-number flows by employing minimal-span channels (Jimenez & Moin 1991). Proof-of-concept simulations demonstrate that flows in minimal-span channels are sufficient for capturing the downward velocity shift, that is, the Hama roughness function, predicted by flows in full-span channels. We consider two sets of simulations, first with modelled roughness imposed by body forces, and second with explicit roughness described by roughness-conforming grids. Owing to the minimal cost, we are able to conduct DNSs with increasing roughness Reynolds numbers while maintaining a fixed blockage ratio, as is typical in full-scale applications. The present method promises a practical, fast and accurate tool for character...

  13. Direct Experimental Simulation of the Yang-Baxter Equation

    E-Print Network [OSTI]

    Chao Zheng; Jun-lin Li; Si-yu Song; Gui Lu Long

    2013-05-27

    Introduced in the field of many-body statistical mechanics, Yang-Baxter equation has become an important tool in a variety fields of physics. In this work, we report the first direct experimental simulation of the Yang-Baxter equation using linear quantum optics. The equality between the two sides of the Yang-Baxter equation in two dimension has been demonstrated directly, and the spectral parameter transformation in the Yang-Baxter equation is explicitly confirmed.

  14. Direct Numerical Simulations and Modeling of Jets in Crossflow

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies

  15. Control of Jets in Crossflow using Direct Numerical Simulations

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Control of Jets in Crossflow using Direct Numerical Simulations A THESIS SUBMITTED TO THE FACULTY in crossflow by axial pulsing. Our main idea is that pulsing generates vortex rings; the effect of pulsing on jets in crossflow can therefore be explained by studying the behavior of vortex rings in crossflow

  16. Direct Monte Carlo simulation of chemical reaction systems: Dissociation and recombination

    E-Print Network [OSTI]

    Anderson, James B.

    Direct Monte Carlo simulation of chemical reaction systems: Dissociation and recombination Shannon Carlo simulations of a chemical reaction system with bimolecular and termolecular dissociation­8 to be well suited for treating chemical reaction systems with nonequilibrium distributions, coupled gas

  17. Simulation of directional solidification, thermochemical convection, and chimney formation in a Hele-Shaw cell

    E-Print Network [OSTI]

    Worster, M. Grae

    Simulation of directional solidification, thermochemical convection, and chimney formation and the Enthalpy Method throughout the computational domain allows us to avoid prescribing internal boundary

  18. The Development of A Human Systems Simulation Laboratory: Strategic Direction

    SciTech Connect (OSTI)

    Jacques Hugo; Katya le Blanc; David Gertman

    2012-07-01

    The Human System Simulation Laboratory (HSSL) at the Idaho National Laboratory is one of few facilities of its kind that allows human factors researchers to evaluate various aspects of human performance and human system interaction for proposed reactor designs and upgrades. A basic system architecture, physical configuration and simulation capability were established to enable human factors researchers to support multiple, simultaneous simulations and also different power plant technologies. Although still evolving in terms of its technical and functional architecture, the HSSL is already proving its worth in supporting current and future nuclear industry needs for light water reactor sustainability and small modular reactors. The evolution of the HSSL is focused on continual physical and functional refinement to make it a fully equipped, reconfigurable facility where advanced research, testing and validation studies can be conducted on a wider range of reactor technologies. This requires the implementation of additional plant models to produce empirical research data on human performance with emerging human-system interaction technologies. Additional beneficiaries of this information include system designers and HRA practitioners. To ensure that results of control room crew studies will be generalizable to the existing and evolving fleet of US reactors, future expansion of the HSSL may also include other SMR plant models, plant-specific simulators and a generic plant model aligned to the current generation of pressurized water reactors (PWRs) and future advanced reactor designs. Collaboration with industry partners is also proving to be a vital component of the facility as this helps to establish a formal basis for current and future human performance experiments to support nuclear industry objectives. A long-range Program Plan has been developed for the HSSL to ensure that the facility will support not only the Department of Energy’s Light Water Reactor Sustainability Program, but also to provide human factors guidance for all future developments of the nuclear industry.

  19. DYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION

    E-Print Network [OSTI]

    for intended deployment in large arrays of dishes, with steam directed to a central large steam turbine powerDYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION José Zapata 1 , John dish has been in operation since 2010 with a mono-tube steam cavity receiver, the SG4 system

  20. Three-Dimensional Simulations of Liquid Feed Direct Methanol Wenpeng Liu*,a

    E-Print Network [OSTI]

    Three-Dimensional Simulations of Liquid Feed Direct Methanol Fuel Cells Wenpeng Liu*,a and Chao that performance and design of a liquid feed direct methanol fuel cell DMFC is controlled not only by electrochemical kinetics and methanol crossover but also by water transport and by their complex interactions

  1. Direct Monte Carlo simulation of chemical reaction systems: Internal energy transfer and an energy-dependent unimolecular reaction

    E-Print Network [OSTI]

    Anderson, James B.

    Direct Monte Carlo simulation of chemical reaction systems: Internal energy transfer and an energy a direct Monte Carlo simulation of an energy-dependent t&molecular reaction system of the type A+ B simulation of a unimo- lecular reaction with an energy-dependent rate constant k3 and with explicit treatment

  2. Direct Monte Carlo simulation of chemical reaction systems: Simple bimolecular reactions

    E-Print Network [OSTI]

    Anderson, James B.

    Direct Monte Carlo simulation of chemical reaction systems: Simple bimolecular reactions Shannon D and understanding the behavior of gas phase chemical reaction systems. This Monte Carlo method, originated by Bird. Extension to chemical reactions offers a powerful tool for treating reaction systems with nonthermal

  3. Reaction ensemble molecular dynamics: Direct simulation of the dynamic equilibrium properties of chemically reacting mixtures

    E-Print Network [OSTI]

    Lisal, Martin

    diffusion) as well as reaction equilibria for chemically reacting mixtures. DOI: 10.1103/PhysRevE.70.) on chemical reaction equilibria is critical in many fields of science including mixture separationReaction ensemble molecular dynamics: Direct simulation of the dynamic equilibrium properties

  4. Direct numerical simulation of turbulent heat transfer in annuli: effect of heat flux ratio.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Direct numerical simulation of turbulent heat transfer in annuli: effect of heat flux ratio. M-la-Vall´ee cedex 2, France (Dated: October 23, 2008) Abstract Fully developed turbulent flow and heat transfer square (rms) of temperature fluctuations, turbulent heat fluxes, heat transfer, ...). To validate

  5. Direct Simulations of Homogeneous Bubble Nucleation: Agreement with CNT and no Local Hot Spots

    E-Print Network [OSTI]

    Jürg Diemand; Raymond Angélil; Kyoko K. Tanaka; Hidekazu Tanaka

    2014-10-24

    We present results from direct, large-scale molecular dynamics (MD) simulations of homogeneous bubble (liquid-to-vapor) nucleation. The simulations contain half a billion Lennard-Jones (LJ) atoms and cover up to 56 million time-steps. The unprecedented size of the simulated volumes allows us to resolve the nucleation and growth of many bubbles per run in simple direct micro-canonical (NVE) simulations while the ambient pressure and temperature remain almost perfectly constant. We find bubble nucleation rates which are lower than in most of the previous, smaller simulations. It is widely believed that classical nucleation theory (CNT) generally underestimates bubble nucleation rates by very large factors. However, our measured rates are within two orders of magnitude of CNT predictions - only at very low temperatures does CNT underestimate the nucleation rate significantly. Introducing a small, positive Tolman length leads to very good agreement at all temperatures, as found in our recent vapor-to-liquid nucleation simulations. The critical bubbles sizes derived with the nucleation theorem agree well with the CNT predictions at all temperatures. Local hot spots reported in the literature are not seen: Regions where a bubble nucleation events will occur are not above the average temperature, and no correlation of temperature fluctuations with subsequent bubble formation is seen.

  6. Performance analysis of direct N-body algorithms for astrophysical simulations on distributed systems

    E-Print Network [OSTI]

    Alessia Gualandris; Simon Portegies Zwart; Alfredo Tirado-Ramos

    2007-01-08

    We discuss the performance of direct summation codes used in the simulation of astrophysical stellar systems on highly distributed architectures. These codes compute the gravitational interaction among stars in an exact way and have an O(N^2) scaling with the number of particles. They can be applied to a variety of astrophysical problems, like the evolution of star clusters, the dynamics of black holes, the formation of planetary systems, and cosmological simulations. The simulation of realistic star clusters with sufficiently high accuracy cannot be performed on a single workstation but may be possible on parallel computers or grids. We have implemented two parallel schemes for a direct N-body code and we study their performance on general purpose parallel computers and large computational grids. We present the results of timing analyzes conducted on the different architectures and compare them with the predictions from theoretical models. We conclude that the simulation of star clusters with up to a million particles will be possible on large distributed computers in the next decade. Simulating entire galaxies however will in addition require new hybrid methods to speedup the calculation.

  7. Direct numerical simulations of fluid flow, heat transfer and phase changes

    SciTech Connect (OSTI)

    Juric, D.; Tryggvason, G.; Han, J.

    1997-04-01

    Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.

  8. Using Direct Sub-Level Entity Access to Improve Nuclear Stockpile Simulation Modeling

    SciTech Connect (OSTI)

    Robert Y. Parker

    1999-08-01

    Direct sub-level entity access is a seldom-used technique in discrete-event simulation modeling that addresses the accessibility of sub-level entity information. The technique has significant advantages over more common, alternative modeling methods--especially where hierarchical entity structures are modeled. As such, direct sub-level entity access is often preferable in modeling nuclear stockpile, life-extension issues, an area to which it has not been previously applied. Current nuclear stockpile, life-extension models were demonstrated to benefit greatly from the advantages of direct sub-level entity access. In specific cases, the application of the technique resulted in models that were up to 10 times faster than functionally equivalent models where alternative techniques were applied. Furthermore, specific implementations of direct sub-level entity access were observed to be more flexible, efficient, functional, and scalable than corresponding implementations using common modeling techniques. Common modeling techniques (''unbatch/batch'' and ''attribute-copying'') proved inefficient and cumbersome in handling many nuclear stockpile modeling complexities, including multiple weapon sites, true defect analysis, and large numbers of weapon and subsystem types. While significant effort was required to enable direct sub-level entity access in the nuclear stockpile simulation models, the enhancements were worth the effort--resulting in more efficient, more capable, and more informative models that effectively addressed the complexities of the nuclear stockpile.

  9. Simulation and Experiment on Direct Continuous Casting Process of Lead Frame Copper Alloy

    SciTech Connect (OSTI)

    Huang Guojie; Xie Shuisheng; Cheng Lei [State Key Laboratory for Fabrication and Process of Nonferrous Metals, Beijing General Research Institute for Non-ferrous Metals, 100088 (China)

    2010-06-15

    Direct Continuous Casting (D.C.C) is an important method in casting lead frame copper alloy. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the D.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1413 Kapprox1413 K, the casting speed is between 8 m/happrox10 m/h and the speed of cooling water is between 4.2 m/sapprox4.6 m/s. And the depth of liquid-solid boundary is measured in different casting temperature and casting speed by experiments. The results show the actual measurements have a little deviation with the numerical simulation. The results of numerical simulation provide the significant reference to the actual experiments.

  10. Monte Carlo Simulations of Globular Cluster Evolution. IV. Direct Integration of Strong Interactions

    E-Print Network [OSTI]

    John M. Fregeau; Frederic A. Rasio

    2006-12-06

    We study the dynamical evolution of globular clusters containing populations of primordial binaries, using our newly updated Monte Carlo cluster evolution code with the inclusion of direct integration of binary scattering interactions. We describe the modifications we have made to the code, as well as improvements we have made to the core Monte Carlo method. We present several test calculations to verify the validity of the new code, and perform many comparisons with previous analytical and numerical work in the literature. We simulate the evolution of a large grid of models, with a wide range of initial cluster profiles, and with binary fractions ranging from 0 to 1, and compare with observations of Galactic globular clusters. We find that our code yields very good agreement with direct N-body simulations of clusters with primordial binaries, but yields some results that differ significantly from other approximate methods. Notably, the direct integration of binary interactions reduces their energy generation rate relative to the simple recipes used in Paper III, and yields smaller core radii. Our results for the structural parameters of clusters during the binary-burning phase are now in the tail of the range of parameters for observed clusters, implying that either clusters are born significantly more or less centrally concentrated than has been previously considered, or that there are additional physical processes beyond two-body relaxation and binary interactions that affect the structural characteristics of clusters.

  11. Simulation of direct plasma injection for laser ion beam acceleration with a radio frequency quadrupole

    SciTech Connect (OSTI)

    Jin, Q. Y.; Li, Zh. M.; Liu, W.; Zhao, H. Y. Zhang, J. J.; Sha, Sh.; Zhang, Zh. L.; Zhang, X. Zh.; Sun, L. T.; Zhao, H. W.

    2014-07-15

    The direct plasma injection scheme (DPIS) has been being studied at Institute of Modern Physics since several years ago. A C{sup 6+} beam with peak current of 13 mA, energy of 593 keV/u has been successfully achieved after acceleration with DPIS method. To understand the process of DPIS, some simulations have been done as follows. First, with the total current intensity and the relative yields of different charge states for carbon ions measured at the different distance from the target, the absolute current intensities and time-dependences for different charge states are scaled to the exit of the laser ion source in the DPIS. Then with these derived values as the input parameters, the extraction of carbon beam from the laser ion source to the radio frequency quadrupole with DPIS is simulated, which is well agreed with the experiment results.

  12. Estimation of direct laser acceleration in laser wakefield accelerators using particle-in-cell simulations

    E-Print Network [OSTI]

    Shaw, J L; Marsh, K A; Tsung, F S; Mori, W B; Joshi, C

    2015-01-01

    Many current laser wakefield acceleration (LWFA) experiments are carried out in a regime where the laser pulse length is on the order of or longer than the wake wavelength and where ionization injection is employed to inject electrons into the wake. In these experiments, the trapped electrons will co-propagate with the longitudinal wakefield and the transverse laser field. In this scenario, the electrons can gain a significant amount of energy from both the direct laser acceleration (DLA) mechanism as well as the usual LWFA mechanism. Particle-in-cell (PIC) codes are frequently used to discern the relative contribution of these two mechanisms. However, if the longitudinal resolution used in the PIC simulations is inadequate, it can produce numerical heating that can overestimate the transverse motion, which is important in determining the energy gain due to DLA. We have therefore carried out a systematic study of this LWFA regime by varying the longitudinal resolution of PIC simulations from the standard, bes...

  13. Electron nanoprobe induced oxidation: A simulation of direct-write purification

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fowlkes, J. D.; Geier, B.; Lewis, B. B.; Rack, P. D.; Stanford, M. G.; Winkler, R.; Plank, H.

    2015-06-01

    Electron beam direct-write has recently taken a large step forward with the advent of methods to purify deposits. This development has opened the door for future direct-write device prototyping and editing. In one such approach, an additional beam scanning procedure removes carbonaceous impurities via oxidation from metal–carbon deposits (e.g., PtC5) in the presence of H2O or O2 after deposition. So far, critical aspects of the oxidation reaction remain unclear; experiments reveal clearly that electron stimulated oxidation drives the process yet it is not understood why H2O purifies by a bottom-up mechanism while O2 purifies from the top-down. The simulation resultsmore »presented here suggest that the chemisorption of dissolved O2 at buried Pt nanoparticle surfaces controls purification in the top-down case while both the high relative solubility coupled with weak physisorption of H2O explains the bottom-up process. Crucial too is the role that the carbonaceous contaminant itself has on the dissolution and diffusion of O2 and H2O. The results pave the way for simulation driven experiments where (1) the transient densification of the deposit can be accounted for in the initial deposit design stage and (2) the deposition and purification steps can be combined.« less

  14. Simulation of an Ar/NH{sub 3} low pressure magnetized direct current discharge

    SciTech Connect (OSTI)

    Li Zhi [School of Science, University of Science and Technology Liaoning, Anshan 114051 (China); School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao Zhen [School of Chemistry and Life Science, Anshan Normal University, Anshan 114007 (China); School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Li Xuehui [Physiccal Science and Technical College, Dalian University, Dalian 116622 (China)

    2013-01-15

    A two-dimensional fluid model has been used to investigate the properties of plasma in an Ar/NH{sub 3} low pressure magnetized direct current discharge. We compared the simulation results with the theoretical and experimental results of the other gas discharge in which the magnetic field is considered. Results that obtained using this method are in good agreement with literature. The simulation results show that the positive ammonia ion density follows the positive argon ion density. The Ar{sub 2}{sup +} density is slightly higher than the Ar{sup +} density at 100 mTorr. The largest ammonia ion is NH{sub 3}{sup +} ion, followed by NH{sub 2}{sup +}, NH{sub 4}{sup +}, and NH{sup +} ions. The contribution of NH{sup +} ions to the density of the positive ammonia ions is marginal. The influence of pressure on the plasma discharge has been studied by simulation, and the mechanisms have been discussed. The average plasma density increases as pressure increased. The plasma density appears to be more inhomogeneous than that at the lower pressure. The ratio of charge particles changed as pressure increased. The Ar{sup +} density is slightly higher than the Ar{sub 2}{sup +} density as the pressure increased. It makes NH{sub 4}{sup +} ratio increase as pressure increased. It shows that the electron temperature drops with rising pressure by numerical calculation.

  15. 43rd AIAA Aerospace Sciences Meeting and Exhibit, Jan 1013, Reno, Nevada Direct numerical simulation of turbulent jets in crossflow

    E-Print Network [OSTI]

    Mahesh, Krishnan

    simulation of turbulent jets in crossflow Suman Muppidi and Krishnan Mahesh University of Minnesota, Minneapolis, MN, 55455, USA Direct numerical simulations are used to study a round turbulent jet in a laminar crossflow. The velocity ratio of the jet to that of the crossflow is 5.7 and the Reynolds number based

  16. Field simulation of axisymmetric plasma screw pinches by alternating-direction-implicit methods

    SciTech Connect (OSTI)

    Lambert, M.A.

    1996-06-01

    An axisymmetric plasma screw pinch is an axisymmetric column of ionized gaseous plasma radially confined by forces from axial and azimuthal currents driven in the plasma and its surroundings. This dissertation is a contribution to detailed, high resolution computer simulation of dynamic plasma screw pinches in 2-d {ital rz}-coordinates. The simulation algorithm combines electron fluid and particle-in-cell (PIC) ion models to represent the plasma in a hybrid fashion. The plasma is assumed to be quasineutral; along with the Darwin approximation to the Maxwell equations, this implies application of Ampere`s law without displacement current. Electron inertia is assumed negligible so that advective terms in the electron momentum equation are ignored. Electrons and ions have separate scalar temperatures, and a scalar plasma electrical resistivity is assumed. Altemating-direction-implicit (ADI) methods are used to advance the electron fluid drift velocity and the magnetic fields in the simulation. The ADI methods allow time steps larger than allowed by explicit methods. Spatial regions where vacuum field equations have validity are determined by a cutoff density that invokes the quasineutral vacuum Maxwell equations (Darwin approximation). In this dissertation, the algorithm was first checked against ideal MM stability theory, and agreement was nicely demonstrated. However, such agreement is not a new contribution to the research field. Contributions to the research field include new treatments of the fields in vacuum regions of the pinch simulation. The new treatments predict a level of magnetohydrodynamic turbulence near the bulk plasma surface that is higher than predicted by other methods.

  17. Terascale direct numerical simulations of turbulent combustion using S3D

    SciTech Connect (OSTI)

    Chen, Jackie; Klasky, Scott A; Hawkes, Evatt R; Sankaran, Ramanan; Choudhary, Alok; Yoo, Chun S; Liao, Wei-keng; Podhorszki, Norbert

    2009-01-01

    Computational science is paramount to the understanding of underlying processes in internal combustion engines of the future that will utilize non-petroleum-based alternative fuels, including carbon-neutral biofuels, and burn in new combustion regimes that will attain high efficiency while minimizing emissions of particulates and nitrogen oxides. Next-generation engines will likely operate at higher pressures, with greater amounts of dilution and utilize alternative fuels that exhibit a wide range of chemical and physical properties. Therefore, there is a significant role for high-fidelity simulations, direct numerical simulations (DNS), specifically designed to capture key turbulence-chemistry interactions in these relatively uncharted combustion regimes, and in particular, that can discriminate the effects of differences in fuel properties. In DNS, all of the relevant turbulence and flame scales are resolved numerically using high-order accurate numerical algorithms. As a consequence terascale DNS are computationally intensive, require massive amounts of computing power and generate tens of terabytes of data. Recent results from terascale DNS of turbulent flames are presented here, illustrating its role in elucidating flame stabilization mechanisms in a lifted turbulent hydrogen/air jet flame in a hot air coflow, and the flame structure of a fuel-lean turbulent premixed jet flame. Computing at this scale requires close collaborations between computer and combustion scientists to provide optimized scaleable algorithms and software for terascale simulations, efficient collective parallel I/O, tools for volume visualization of multiscale, multivariate data and automating the combustion workflow. The enabling computer science, applied to combustion science, is also required in many other terascale physics and engineering simulations. In particular, performance monitoring is used to identify the performance of key kernels in the DNS code, S3D and especially memory intensive loops in the code. Through the careful application of loop transformations, data reuse in cache is exploited thereby reducing memory bandwidth needs, and hence, improving S3D's nodal performance. To enhance collective parallel I/O in S3D, an MPI-I/O caching design is used to construct a two-stage write-behind method for improving the performance of write-only operations. The simulations generate tens of terabytes of data requiring analysis. Interactive exploration of the simulation data is enabled by multivariate time-varying volume visualization. The visualization highlights spatial and temporal correlations between multiple reactive scalar fields using an intuitive user interface based on parallel coordinates and time histogram. Finally, an automated combustion workflow is designed using Kepler to manage large-scale data movement, data morphing, and archival and to provide a graphical display of run-time diagnostics.

  18. A direct numerical simulation method for complex modulus of particle dispersions

    E-Print Network [OSTI]

    T. Iwashita; T. Kumagai; R. Yamamoto

    2010-04-24

    We report an extension of the smoothed profile method (SPM)[Y. Nakayama, K. Kim, and R. Yamamoto, Eur. Phys. J. E {\\bf 26}, 361(2008)], a direct numerical simulation method for calculating the complex modulus of the dispersion of particles, in which we introduce a temporally oscillatory external force into the system. The validity of the method was examined by evaluating the storage $G'(\\omega)$ and loss $G"(\\omega)$ moduli of a system composed of identical spherical particles dispersed in an incompressible Newtonian host fluid at volume fractions of $\\Phi=0$, 0.41, and 0.51. The moduli were evaluated at several frequencies of shear flow; the shear flow used here has a zigzag profile, as is consistent with the usual periodic boundary conditions.

  19. Quasi-spherical direct drive fusion simulations for the Z machine and future accelerators.

    SciTech Connect (OSTI)

    VanDevender, J. Pace; McDaniel, Dillon Heirman; Roderick, Norman Frederick; Nash, Thomas J.

    2007-11-01

    We explored the potential of Quasi-Spherical Direct Drive (QSDD) to reduce the cost and risk of a future fusion driver for Inertial Confinement Fusion (ICF) and to produce megajoule thermonuclear yield on the renovated Z Machine with a pulse shortening Magnetically Insulated Current Amplifier (MICA). Analytic relationships for constant implosion velocity and constant pusher stability have been derived and show that the required current scales as the implosion time. Therefore, a MICA is necessary to drive QSDD capsules with hot-spot ignition on Z. We have optimized the LASNEX parameters for QSDD with realistic walls and mitigated many of the risks. Although the mix-degraded 1D yield is computed to be {approx}30 MJ on Z, unmitigated wall expansion under the > 100 gigabar pressure just before burn prevents ignition in the 2D simulations. A squeezer system of adjacent implosions may mitigate the wall expansion and permit the plasma to burn.

  20. GPU accelerated flow solver for direct numerical simulation of turbulent flows

    SciTech Connect (OSTI)

    Salvadore, Francesco [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy); Bernardini, Matteo, E-mail: matteo.bernardini@uniroma1.it [Department of Mechanical and Aerospace Engineering, University of Rome ‘La Sapienza’ – via Eudossiana 18, 00184 Rome (Italy)] [Department of Mechanical and Aerospace Engineering, University of Rome ‘La Sapienza’ – via Eudossiana 18, 00184 Rome (Italy); Botti, Michela [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)

    2013-02-15

    Graphical processing units (GPUs), characterized by significant computing performance, are nowadays very appealing for the solution of computationally demanding tasks in a wide variety of scientific applications. However, to run on GPUs, existing codes need to be ported and optimized, a procedure which is not yet standardized and may require non trivial efforts, even to high-performance computing specialists. In the present paper we accurately describe the porting to CUDA (Compute Unified Device Architecture) of a finite-difference compressible Navier–Stokes solver, suitable for direct numerical simulation (DNS) of turbulent flows. Porting and validation processes are illustrated in detail, with emphasis on computational strategies and techniques that can be applied to overcome typical bottlenecks arising from the porting of common computational fluid dynamics solvers. We demonstrate that a careful optimization work is crucial to get the highest performance from GPU accelerators. The results show that the overall speedup of one NVIDIA Tesla S2070 GPU is approximately 22 compared with one AMD Opteron 2352 Barcelona chip and 11 compared with one Intel Xeon X5650 Westmere core. The potential of GPU devices in the simulation of unsteady three-dimensional turbulent flows is proved by performing a DNS of a spatially evolving compressible mixing layer.

  1. Terascale Direct Numerical Simulations of Turbulent Combustion: Capabilities and Limits (PReSS Talk)

    SciTech Connect (OSTI)

    Yoo, Chun Sang

    2009-03-26

    The rapid growth in computational capabilities has provided great opportunities for direct numerical simulations (DNS) of turbulent combustion, a type of simulations without any turbulence model. With the help of terascale high performance supercomputing (HPC) resources, we are now able to provide fundamental insight into turbulence-chemistry interaction in simple laboratory-scale turbulent flames with detailed chemistry using three-dimensional (3D) DNS. However, the actual domain size of 3D-DNS is still limited within {approx} O(10 cm{sup 3}) due to its tremendously high grid resolution required to resolve the smallest turbulent length scale as well as flame structures. Moreover, 3D-DNS will require more computing powers to investigate next-generation engines, of which operating conditions will be characterized by higher pressures, lower temperatures, and higher levels of dilution. In this talk, I will discuss the capabilities and limits of DNS of turbulent combustion and present some results of ignition/extinction characteristics of a highly diluted hydrogen flame counter-flowing against heated air. The results of our recent 3D-DNS of a spatially-developing turbulent lifted hydrogen jet flame in heated coflow will also be presented. The 3D-DNS was performed at a jet Reynolds number of 11,000 with {approx} 1 billion grid points, which required 3.5 million CPU hours on Cray XT3/XT4 at Oak Ridge National Laboratories.

  2. Is the Calcite-Water Interface Understood? Direct Comparisons of Molecular Dynamics Simulations with Specular X-ray Reflectivity Data

    SciTech Connect (OSTI)

    Fenter, Paul; Kerisit, Sebastien N.; Raiteri, Paolo; Gale, Julian D.

    2013-04-01

    New insights into the structure of the calcite-water interface are obtained through direct model-independent comparison of multiple classical molecular dynamics (MD) simulations with high-resolution specular X-ray reflectivity (XR) data. This set of comparisons, with four different state-of-the-art force fields (including two non-polarizable, one polarizable, and one reactive force field), reveal new insights into the absolute accuracy of the simulated structures and the uniqueness of the XR-derived structural results. These four simulations, while qualitatively similar, have visibly distinct interfacial structure, and are distinguished through a quantitative comparison of the XR signals calculated from these simulations with experimental XR data. The results demonstrate that the simulated calcite-water interface structures, as a whole, are not consistent with the XR data (i.e., within their precision and accuracy). This disagreement is largely due to the simulation of the calcite lattice. The simulated interfacial water profiles show substantially different levels of agreement with the XR data. Of these, the rigid-ion model (RIM) simulations show the best consistency with the experimental XR data. Further model-dependent comparisons of the structural parameters that describe the interfacial structure (derived from both the MD simulations and the XR data) provide further insight into the sources of differences between these two approaches. Using the new insights from the RIM simulations, new structures of the calcite-water interface consistent with both the experimental data and the simulation are identified and compared to recent results.

  3. Statistical and Directable Methods for Large-Scale Rigid Body Simulation 

    E-Print Network [OSTI]

    Hsu, Shu-Wei

    2013-05-07

    This dissertation describes several techniques to improve performance and controllability of large-scale rigid body simulations. We first describe a statistical simulation method that replaces certain stages of rigid body simulation with a...

  4. SIMULATION AND MOCKUP OF SNS JET-FLOW TARGET WITH WALL JET FOR CAVITATION DAMAGE MITIGATION

    SciTech Connect (OSTI)

    Wendel, Mark W; Geoghegan, Patrick J; Felde, David K

    2014-01-01

    Pressure waves created in liquid mercury pulsed spallation targets at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory induce cavitation damage on the stainless steel target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. Severe through-wall cavitation damage on an internal wall near the beam entrance window has been observed in spent-targets. Surprisingly though, there is very little damage on the walls that bound an annular mercury channel that wraps around the front and outside of the target. The mercury flow through this channel is characterized by smooth, attached streamlines. One theory to explain this lack of damage is that the uni-directional flow biases the direction of the collapsing cavitation bubble, reducing the impact pressure and subsequent damage. The theory has been reinforced by in-beam separate effects data. For this reason, a second-generation SNS mercury target has been designed with an internal wall jet configuration intended to protect the concave wall where damage has been observed. The wall jet mimics the annular flow channel streamlines, but since the jet is bounded on only one side, the momentum is gradually diffused by the bulk flow interactions as it progresses around the cicular path of the target nose. Numerical simulations of the flow through this jet-flow target have been completed, and a water loop has been assembled with a transparent test target in order to visualize and measure the flow field. This paper presents the wall jet simulation results, as well as early experimental data from the test loop.

  5. Directed nanoscale self-assembly of molecular wires interconnecting nodal points using Monte Carlo simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Boscoboinik, A. M.; Manzi, S. J.; Tysoe, W. T.; Pereyra, V. D.; Boscoboinik, J. A.

    2015-09-10

    The influence of directing agents in the self-assembly of molecular wires to produce two-dimensional electronic nanoarchitectures is studied here using a Monte Carlo approach to simulate the effect of arbitrarily locating nodal points on a surface, from which the growth of self-assembled molecular wires can be nucleated. This is compared to experimental results reported for the self-assembly of molecular wires when 1,4-phenylenediisocyanide (PDI) is adsorbed on Au(111). The latter results in the formation of (Au-PDI)n organometallic chains, which were shown to be conductive when linked between gold nanoparticles on an insulating substrate. The present study analyzes, by means of stochasticmore »methods, the influence of variables that affect the growth and design of self-assembled conductive nanoarchitectures, such as the distance between nodes, coverage of the monomeric units that leads to the formation of the desired architectures, and the interaction between the monomeric units. As a result, this study proposes an approach and sets the stage for the production of complex 2D nanoarchitectures using a bottom-up strategy but including the use of current state-of-the-art top-down technology as an integral part of the self-assembly strategy.« less

  6. Direct Vlasov simulations of electron-attracting cylindrical Langmuir probes in flowing plasmas

    SciTech Connect (OSTI)

    Sánchez-Arriaga, G.; Pastor-Moreno, D.

    2014-07-15

    Current collection by positively polarized cylindrical Langmuir probes immersed in flowing plasmas is analyzed using a non-stationary direct Vlasov-Poisson code. A detailed description of plasma density spatial structure as a function of the probe-to-plasma relative velocity U is presented. Within the considered parametric domain, the well-known electron density maximum close to the probe is weakly affected by U. However, in the probe wake side, the electron density minimum becomes deeper as U increases and a rarified plasma region appears. Sheath radius is larger at the wake than at the front side. Electron and ion distribution functions show specific features that are the signature of probe motion. In particular, the ion distribution function at the probe front side exhibits a filament with positive radial velocity. It corresponds to a population of rammed ions that were reflected by the electric field close to the positively biased probe. Numerical simulations reveal that two populations of trapped electrons exist: one orbiting around the probe and the other with trajectories confined at the probe front side. The latter helps to neutralize the reflected ions, thus explaining a paradox in past probe theory.

  7. Test particle simulation of direct laser acceleration in a density-modulated plasma waveguide

    SciTech Connect (OSTI)

    Lin, M.-W.; Jovanovic, I.

    2012-11-15

    Direct laser acceleration (DLA) of electrons by the use of the intense axial electric field of an ultrafast radially polarized laser pulse is a promising technique for future compact accelerators. Density-modulated plasma waveguides can be implemented for guiding the propagation of the laser pulse to extend the acceleration distance and for the quasi-phase-matching between the accelerated electrons and the laser pulse. A test particle model is developed to study the optimal axial density modulation structure of plasma waveguides for laser pulses to efficiently accelerate co-propagating electrons. A simple analytical approach is also presented, which can be used to estimate the energy gain in DLA. The analytical model is validated by the test particle simulation. The effect of injection phase and acceleration of electrons injected at various radial positions are studied. The results indicate that a positively chirped density modulation of the waveguide structure is required to accelerate electron with low initial energies, and can be effectively optimized. A wider tolerance on the injection phase and radial distance from the waveguide axis exists for electrons injected with a higher initial energy.

  8. Direct

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDirac Charge Dynamcs inDirect

  9. Directions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum FuelEnergy InnovationDirections

  10. Direct numerical simulations of type Ia supernovae flames II: The rayleigh-taylor instability

    E-Print Network [OSTI]

    Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

    2004-01-01

    Weaver, T. A. 1994, in Supernovae, Les Houches, Session LIV,Simulations of Type Ia Supernovae Flames II: The Rayleigh-Subject headings: supernovae: general — white dwarfs —

  11. Direct numerical simulations of type Ia supernovae flames I: The landau-darrieus instability

    E-Print Network [OSTI]

    Bell, J.B.; Day, M.S.; Rendleman, C.A.; Woosley, S.E.; Zingale, M.

    2003-01-01

    Simulations of Type Ia Supernovae Flames I: The Landau-Subject headings: supernovae: general — white dwarfs —could occur in Type Ia supernovae (Niemeyer & Woosley 1997),

  12. Direct Numerical Simulation of Pore-Scale Flow in a Bead Pack: Comparison with Magnetic Resonance Imaging Observations

    SciTech Connect (OSTI)

    Yang, Xiaofan; Scheibe, Timothy D.; Richmond, Marshall C.; Perkins, William A.; Vogt, Sarah J.; Codd, Sarah L.; Seymour, Joseph D.; Mckinley, Matthew I.

    2013-04-01

    A significant body of current research is aimed at developing methods for numerical simulation of flow and transport in porous media that explicitly resolve complex pore and solid geometries, and at utilizing such models to study the relationships between fundamental pore-scale processes and macroscopic manifestations at larger (i.e., Darcy) scales. A number of different numerical methods for pore-scale simulation have been developed, and have been extensively tested and validated for simplified geometries. However, validation of pore-scale simulations of fluid velocity for complex, three-dimensional (3D) pore geometries that are representative of natural porous media is challenging due to our limited ability to measure pore-scale velocity in such systems. Recent advances in magnetic resonance imaging (MRI) offer the opportunity to measure not only the pore geometry, but also local fluid velocities under steady-state flow conditions in 3D and with high spatial resolution. In this paper, we present a 3D velocity field measured at sub-pore resolution (tens of micrometers) over a centimeter-scale 3D domain using MRI methods. We have utilized the measured pore geometry to perform 3D simulations of Navier-Stokes flow over the same domain using direct numerical simulation techniques. We present a comparison of the numerical simulation results with the measured velocity field. It is shown that the numerical results match the observed velocity patterns well overall except for a variance and small systematic scaling which can be attributed to the known experimental error in the MRI measurements. The comparisons presented here provide strong validation of the pore-scale simulation methods and new insights for interpretation of uncertainty in MRI measurements of pore-scale velocity. This study also provides a potential benchmark for future comparison of other pore-scale simulation methods.

  13. Massively-Parallel Direct Numerical Simulation of Gas Turbine Endwall Film-Cooling Conjugate Heat Transfer 

    E-Print Network [OSTI]

    Meador, Charles Michael

    2011-02-22

    Improvements to gas turbine efficiency depend closely on cooling technologies, as efficiency increases with turbine inlet temperature. To aid in this process, simulations that consider real engine conditions need to be ...

  14. Direct Simulation Monte Carlo (DSMC) and Navier-Stokes calculations are performed for a Mach 11

    E-Print Network [OSTI]

    Roy, Chris

    , with separation occurring at the cone-cone juncture. The simulations ac- count for thermochemical nonequilibrium general solution variable Ho stagnation or total enthalpy, J/kg h specific enthalpy, J/kg p pressure, N/m2

  15. ESRDC ship notional baseline Medium Voltage Direct Current (MVDC) architecture thermal simulation and visualization

    E-Print Network [OSTI]

    Chryssostomidis, Chryssostomos

    2011-01-01

    This work presents a fast visualization and thermal simulation tool developed as part of the Electric Ship Research and Development Consortium (ESRDC) funded by the Office of Naval Research (ONR) that is capable of providing ...

  16. Low frequency, electrodynamic simulation of kinetic plasmas with the DArwin Direct Implicit Particle-In-Cell (DADIPIC) method

    SciTech Connect (OSTI)

    Gibbons, M.R.

    1995-06-01

    This dissertation describes a new algorithm for simulating low frequency, kinetic phenomena in plasmas. DArwin Direct Implicit Particle-in-Cell (DADIPIC), as its name implies, is a combination of the Darwin and direct implicit methods. One of the difficulties in simulating plasmas lies in the enormous disparity between the fundamental scale lengths of a plasma and the scale lengths of the phenomena of interest. The objective is to create models which can ignore the fundamental constraints without eliminating relevant plasma properties. Over the past twenty years several PIC methods have been investigated for overcoming the constraints on explicit electrodynamic PIC. These models eliminate selected high frequency plasma phenomena while retaining kinetic phenomena at low frequency. This dissertation shows that the combination of Darwin and Direct Implicit allows them to operate better than they have been shown to operate in the past. Through the Darwin method the hyperbolic Maxwell`s equations are reformulated into a set of elliptic equations. Propagating light waves do not exist in the formulation so the Courant constraint on the time step is eliminated. The Direct Implicit method is applied only to the electrostatic field with the result that electrostatic plasma oscillations do not have to be resolved for stability. With the elimination of these constraints spatial and temporal discretization can be much larger than that possible with explicit, electrodynamic PIC. The code functions in a two dimensional Cartesian region and has been implemented with all components of the particle velocities, the E-field, and the B-field. Internal structures, conductors or dielectrics, may be placed in the simulation region, can be set at desired potentials, and driven with specified currents.

  17. Solving future problems: Default network and executive activity associated with goal-directed mental simulations

    E-Print Network [OSTI]

    Spreng, R. Nathan

    Solving future problems: Default network and executive activity associated with goal are often focused on a goal in the future or a problem to be solved. Recent neuroimaging studies have, we designed a problem-solving task in which participants simulated solving several speci c problems

  18. Solar Energy 74 (2003) 157173 Comparison between ray-tracing simulations and bi-directional

    E-Print Network [OSTI]

    2003-01-01

    Solar Energy 74 (2003) 157­173 Comparison between ray-tracing simulations and bi-Louis Scartezzini a Solar Energy and Building Physics Laboratory LESO-PB, Swiss Federal Institute of Technology EPFL Cyclotron Road, MS 2-300, Berkeley, CA 94720-8134, USA Abstract Evaluation of solar heat gain and daylight

  19. DIRECT NUMERICAL SIMULATIONS OF REFLECTION-DRIVEN, REDUCED MAGNETOHYDRODYNAMIC TURBULENCE FROM THE SUN TO THE ALFVÉN CRITICAL POINT

    SciTech Connect (OSTI)

    Perez, Jean Carlos; Chandran, Benjamin D. G.

    2013-10-20

    We present direct numerical simulations of inhomogeneous reduced magnetohydrodynamic (RMHD) turbulence between the Sun and the Alfvén critical point. These are the first such simulations that take into account the solar-wind outflow velocity and the radial inhomogeneity of the background solar wind without approximating the nonlinear terms in the governing equations. RMHD turbulence is driven by outward-propagating Alfvén waves (z {sup +} fluctuations) launched from the Sun, which undergo partial non-WKB reflection to produce sunward-propagating Alfvén waves (z {sup –} fluctuations). We present 10 simulations with different values of the correlation time ?{sub c{sub sun}{sup +}} and perpendicular correlation length L{sub ?} of outward-propagating Alfvén waves at the coronal base. We find that between 15% and 33% of the z {sup +} energy launched into the corona dissipates between the coronal base and Alfvén critical point. Between 33% and 40% of this input energy goes into work on the solar-wind outflow, and between 22% and 36% escapes as z {sup +} fluctuations through the simulation boundary at r = r{sub A}. The z {sup ±} power spectra scale like k{sub perpendicular}{sup -?{sup ±}}, where k is the wavenumber in the plane perpendicular to B{sub 0}. In our simulation with the smallest value of ?{sub c{sub sun}{sup +}} (?2 minutes) and largest value of L{sub ?} (2 × 10{sup 4} km), we find that ?{sup +} decreases approximately linearly with increasing ln (r), reaching a value of 1.3 at r = 11.1 R{sub ?}. Our simulations with larger values of ?{sub c{sub sun}{sup +}} exhibit alignment between the contours of constant ?{sup +}, ?{sup –}, ?{sub 0}{sup +}, and ?{sub 0}{sup -}, where ?{sup ±} are the Elsässer potentials and ?{sub 0}{sup ±} are the outer-scale parallel Elsässer vorticities.

  20. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations

    SciTech Connect (OSTI)

    Baumgaertel, J. A.; Bradley, P. A.; Hsu, S. C.; Cobble, J. A.; Hakel, P.; Tregillis, I. L.; Krasheninnikova, N. S.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Obrey, K. D.; Batha, S.; Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T.

    2014-05-15

    Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

  1. GPU-accelerated simulation of colloidal suspensions with direct hydrodynamic interactions

    E-Print Network [OSTI]

    Kopp, Michael

    2012-01-01

    Solvent-mediated hydrodynamic interactions between colloidal particles can significantly alter their dynamics. We discuss the implementation of Stokesian dynamics in leading approximation for streaming processors as provided by the compute unified device architecture (CUDA) of recent graphics processors (GPUs). Thereby, the simulation of explicit solvent particles is avoided and hydrodynamic interactions can easily be accounted for in already available, highly accelerated molecular dynamics simulations. Special emphasis is put on efficient memory access and numerical stability. The algorithm is applied to the periodic sedimentation of a cluster of four suspended particles. Finally, we investigate the runtime performance of generic memory access patterns of complexity $O(N^2)$ for various GPU algorithms relying on either hardware cache or shared memory.

  2. Three-Dimensional Simulations of Bi-Directed Magnetohydrodynamic Jets Interacting with Cluster Environments

    E-Print Network [OSTI]

    O'Neill, S M

    2010-01-01

    We report on a series of three-dimensional magnetohydrodynamic simulations of active galactic nucleus (AGN) jet propagation in realistic models of magnetized galaxy clusters. We are primarily interested in the details of energy transfer between jets and the intracluster medium (ICM) to help clarify what role such flows could have in the reheating of cluster cores. Our simulated jets feature a range of intermittency behaviors, including intermittent jets that periodically switch on and off and one model jet that shuts down completely, naturally creating a relic plume. The ICM into which these jets propagate incorporates tangled magnetic field geometries and density substructure designed to mimic some likely features of real galaxy clusters. We find that our jets are characteristically at least 60% efficient at transferring thermal energy to the ICM. Irreversible heat energy is not uniformly distributed, however, instead residing preferentially in regions very near the jet/cocoon boundaries. While intermittency...

  3. Towards Direct Simulation of Future Tropical Cyclone Statistics in a High-Resolution Global Atmospheric Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wehner, Michael F.; Bala, G.; Duffy, Phillip; Mirin, Arthur A.; Romano, Raquel

    2010-01-01

    We present a set of high-resolution global atmospheric general circulation model (AGCM) simulations focusing on the model's ability to represent tropical storms and their statistics. We find that the model produces storms of hurricane strength with realistic dynamical features. We also find that tropical storm statistics are reasonable, both globally and in the north Atlantic, when compared to recent observations. The sensitivity of simulated tropical storm statistics to increases in sea surface temperature (SST) is also investigated, revealing that a credible late 21st century SST increase produced increases in simulated tropical storm numbers and intensities in all ocean basins. Whilemore »this paper supports previous high-resolution model and theoretical findings that the frequency of very intense storms will increase in a warmer climate, it differs notably from previous medium and high-resolution model studies that show a global reduction in total tropical storm frequency. However, we are quick to point out that this particular model finding remains speculative due to a lack of radiative forcing changes in our time-slice experiments as well as a focus on the Northern hemisphere tropical storm seasons.« less

  4. Study of Particle Rotation Effect in Gas-Solid Flows using Direct Numerical Simulation with a Lattice Boltzmann Method

    SciTech Connect (OSTI)

    Kwon, Kyung; Fan, Liang-Shih; Zhou, Qiang; Yang, Hui

    2014-09-30

    A new and efficient direct numerical method with second-order convergence accuracy was developed for fully resolved simulations of incompressible viscous flows laden with rigid particles. The method combines the state-of-the-art immersed boundary method (IBM), the multi-direct forcing method, and the lattice Boltzmann method (LBM). First, the multi-direct forcing method is adopted in the improved IBM to better approximate the no-slip/no-penetration (ns/np) condition on the surface of particles. Second, a slight retraction of the Lagrangian grid from the surface towards the interior of particles with a fraction of the Eulerian grid spacing helps increase the convergence accuracy of the method. An over-relaxation technique in the procedure of multi-direct forcing method and the classical fourth order Runge-Kutta scheme in the coupled fluid-particle interaction were applied. The use of the classical fourth order Runge-Kutta scheme helps the overall IB-LBM achieve the second order accuracy and provides more accurate predictions of the translational and rotational motion of particles. The preexistent code with the first-order convergence rate is updated so that the updated new code can resolve the translational and rotational motion of particles with the second-order convergence rate. The updated code has been validated with several benchmark applications. The efficiency of IBM and thus the efficiency of IB-LBM were improved by reducing the number of the Lagragian markers on particles by using a new formula for the number of Lagrangian markers on particle surfaces. The immersed boundary-lattice Boltzmann method (IBLBM) has been shown to predict correctly the angular velocity of a particle. Prior to examining drag force exerted on a cluster of particles, the updated IB-LBM code along with the new formula for the number of Lagrangian markers has been further validated by solving several theoretical problems. Moreover, the unsteadiness of the drag force is examined when a fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. The simulation results agree well with the theories for the short- and long-time behavior of the drag force. Flows through non-rotational and rotational spheres in simple cubic arrays and random arrays are simulated over the entire range of packing fractions, and both low and moderate particle Reynolds numbers to compare the simulated results with the literature results and develop a new drag force formula, a new lift force formula, and a new torque formula. Random arrays of solid particles in fluids are generated with Monte Carlo procedure and Zinchenko's method to avoid crystallization of solid particles over high solid volume fractions. A new drag force formula was developed with extensive simulated results to be closely applicable to real processes over the entire range of packing fractions and both low and moderate particle Reynolds numbers. The simulation results indicate that the drag force is barely affected by rotational Reynolds numbers. Drag force is basically unchanged as the angle of the rotating axis varies.

  5. A Simple Multi-Directional Absorbing Layer Method to Simulate Elastic Wave Propagation in Unbounded Domains

    E-Print Network [OSTI]

    Semblat, Jean-François; Gandomzadeh, Ali

    2010-01-01

    The numerical analysis of elastic wave propagation in unbounded media may be difficult due to spurious waves reflected at the model artificial boundaries. This point is critical for the analysis of wave propagation in heterogeneous or layered solids. Various techniques such as Absorbing Boundary Conditions, infinite elements or Absorbing Boundary Layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this paper, a simple absorbing layer method is proposed: it is based on a Rayleigh/Caughey damping formulation which is often already available in existing Finite Element softwares. The principle of the Caughey Absorbing Layer Method is first presented (including a rheological interpretation). The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types and inci...

  6. Direct Simulations of Wind-Driven Breaking Ocean Waves with Data Assimilation

    E-Print Network [OSTI]

    Dommermuth, Douglas G; Tran, Vu H; Valenciano, Miguel A

    2014-01-01

    A formulation is developed to assimilate ocean-wave data into the Numerical Flow Analysis (NFA) code. NFA is a Cartesian-based implicit Large-Eddy Simulation (LES) code with Volume of Fluid (VOF) interface capturing. The sequential assimilation of data into NFA permits detailed analysis of ocean-wave physics with higher bandwidths than is possible using either other formulations, such as High-Order Spectral (HOS) methods, or field measurements. A framework is provided for assimilating the wavy and vortical portions of the flow. Nudging is used to assimilate wave data at low wavenumbers, and the wave data at high wavenumbers form naturally through nonlinear interactions, wave breaking, and wind forcing. Similarly, the vertical profiles of the mean vortical flow in the wind and the wind drift are nudged, and the turbulent fluctuations are allowed to form naturally. As a demonstration, the results of a HOS of a JONSWAP wave spectrum are assimilated to study short-crested seas in equilibrium with the wind. Log pr...

  7. Direct $N$-body simulations of globular clusters - II. Palomar 4

    E-Print Network [OSTI]

    Zonoozi, Akram Hasani; Kuepper, Andreas H W; Baumgardt, Holger; Frank, Matthias J; Kroupa, Pavel

    2014-01-01

    We use direct $N$-body calculations to study the evolution of the unusually extended outer halo globular cluster Palomar 4 (Pal~4) over its entire lifetime in order to reproduce its observed mass, half-light radius, velocity dispersion and mass function slope at different radii. We find that models evolving on circular orbits, and starting from a non-mass segregated, canonical initial mass function (IMF) can reproduce neither Pal 4's overall mass function slope nor the observed amount of mass segregation. Including either primordial mass segregation or initially flattened IMFs does not reproduce the observed amount of mass segregation and mass function flattening simultaneously. Unresolved binaries cannot reconcile this discrepancy either. We find that only models with both a flattened IMF and primordial segregation are able to fit the observations. The initial (i.e. after gas expulsion) mass and half-mass radius of Pal~4 in this case are about 57000 M${\\odot}$ and 10 pc, respectively. This configuration is m...

  8. Direct first-principles simulation of a high-performance electron emitter: Lithium-oxide-coated diamond surface

    SciTech Connect (OSTI)

    Miyamoto, Yoshiyuki, E-mail: yoshi-miyamoto@aist.go.jp; Miyazaki, Takehide [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takeuchi, Daisuke; Yamasaki, Satoshi [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); JST, ALCA, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

    2014-09-28

    We examined the field emission properties of lithium(Li)/oxygen(O)-co-terminated diamond (001) surface [C(001)-LiO] through real-time electron dynamics simulation under an applied field. The current emitted from this surface was found to be more than four-fold that emitted by an H-terminated (001) surface, the latter being a typical negative electron affinity system. This high performance is attributed to the Li layer, which bends the potential wall of O-induced electron pockets down in the direction of vacuum, thus facilitating electron emission. Detailed analysis of the emitted electrons and the profile of the self-consistent potential elucidated that the role of O atoms changes from an electron barrier on OH-terminated diamond surfaces to an outlet for electron emission on C(001)-LiO.

  9. An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation

    SciTech Connect (OSTI)

    Rafa, S. Molins; Trebotich, D.; Steefel, C. I.; Shen, C.

    2012-02-01

    The scale-dependence of geochemical reaction rates hinders their use in continuum scale models intended for the interpretation and prediction of chemical fate and transport in subsurface environments such as those considered for geologic sequestration of CO{sub 2}. Processes that take place at the pore scale, especially those involving mass transport limitations to reactive surfaces, may contribute to the discrepancy commonly observed between laboratory-determined and continuum-scale or field rates. Here, the dependence of mineral dissolution rates on the pore structure of the porous media is investigated by means of pore scale modeling of flow and multicomponent reactive transport. The pore scale model is comprised of high performance simulation tools and algorithms for incompressible flow and conservative transport combined with a general-purpose multicomponent geochemical reaction code. The model performs direct numerical simulation of reactive transport based on an operator-splitting approach to coupling transport and reactions. The approach is validated with a Poiseuille flow single-pore experiment and verified with an equivalent 1D continuum-scale model of a capillary tube packed with calcite spheres. Using the case of calcite dissolution as an example, the high resolution model is used to demonstrate that non-uniformity in the flow field at the pore scale has the effect of decreasing the overall reactivity of the system, even when systems with identical reactive surface area are considered. The effect becomes more pronounced as the heterogeneity of the reactive grain packing increases, particularly where the flow slows sufficiently such that the solution approaches equilibrium locally and the average rate becomes transport-limited.

  10. Evidence for Bolgiano-Obukhov scaling in rotating stratified turbulence using high-resolution direct numerical simulations

    SciTech Connect (OSTI)

    Rosenberg, Duane L; Pouquet, Dr. Annick; Mininni, Dr. Pablo D.; Marino, Dr. Raffaele

    2015-01-01

    We report results on rotating stratified turbulence in the absence of forcing, with large-scale isotropic initial conditions, using direct numerical simulations computed on grids of up to $4096^3$ points. The Reynolds and Froude numbers are respectively equal to $Re=5.4\\times 10^4$ and $Fr=0.0242$. The ratio of the Brunt-V\\"ais\\"al\\"a to the inertial wave frequency, $N/f$, is taken to be equal to 5, a choice appropriate to model the dynamics of the southern abyssal ocean at mid latitudes. This gives a global buoyancy Reynolds number $R_B=ReFr^2=32$, a value sufficient for some isotropy to be recovered in the small scales beyond the Ozmidov scale, but still moderate enough that the intermediate scales where waves are prevalent are well resolved. We concentrate on the large-scale dynamics and confirm that the Froude number based on a typical vertical length scale is of order unity, with strong gradients in the vertical. Two characteristic scales emerge from this computation, and are identified from sharp variations in the spectral distribution of either total energy or helicity. A spectral break is also observed at a scale at which the partition of energy between the kinetic and potential modes changes abruptly, and beyond which a Kolmogorov-like spectrum recovers. Large slanted layers are ubiquitous in the flow in the velocity and temperature fields, and a large-scale enhancement of energy is also observed, directly attributable to the effect of rotation.

  11. A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry

    SciTech Connect (OSTI)

    Marxen, Olaf, E-mail: olaf.marxen@vki.ac.be [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States) [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States); Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium); Magin, Thierry E. [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium)] [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chaussée de Waterloo, 72, 1640 Rhode-St-Genèse (Belgium); Shaqfeh, Eric S.G.; Iaccarino, Gianluca [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)] [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)

    2013-12-15

    A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible Navier–Stokes equations using an explicit time advancement scheme and high-order finite differences. This Navier–Stokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as well as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium.

  12. High Performance Direct Gravitational N-body Simulations on Graphics Processing Unit I: An implementation in Cg

    E-Print Network [OSTI]

    Simon Portegies Zwart; Robert Belleman; Peter Geldof

    2007-04-23

    We present the results of gravitational direct $N$-body simulations using the commercial graphics processing units (GPU) NVIDIA Quadro FX1400 and GeForce 8800GTX, and compare the results with GRAPE-6Af special purpose hardware. The force evaluation of the $N$-body problem was implemented in Cg using the GPU directly to speed-up the calculations. The integration of the equations of motions were, running on the host computer, implemented in C using the 4th order predictor-corrector Hermite integrator with block time steps. We find that for a large number of particles ($N \\apgt 10^4$) modern graphics processing units offer an attractive low cost alternative to GRAPE special purpose hardware. A modern GPU continues to give a relatively flat scaling with the number of particles, comparable to that of the GRAPE. The GRAPE is designed to reach double precision, whereas the GPU is intrinsically single-precision. For relatively large time steps, the total energy of the N-body system was conserved better than to one in $10^6$ on the GPU, which is impressive given the single-precision nature of the GPU. For the same time steps, the GRAPE gave somewhat more accurate results, by about an order of magnitude. However, smaller time steps allowed more energy accuracy on the grape, around $10^{-11}$, whereas for the GPU machine precision saturates around $10^{-6}$ For $N\\apgt 10^6$ the GeForce 8800GTX was about 20 times faster than the host computer. Though still about a factor of a few slower than GRAPE, modern GPUs outperform GRAPE in their low cost, long mean time between failure and the much larger onboard memory; the GRAPE-6Af holds at most 256k particles whereas the GeForce 8800GTX can hold 9 million particles in memory.

  13. Analysis of turbulent transport and mixing in transitional Rayleigh/Taylor unstable flow using direct numerical simulation data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

    Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipationmore »and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. These results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.« less

  14. Analysis of turbulent transport and mixing in transitional Rayleigh/Taylor unstable flow using direct numerical simulation data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schilling, Oleg [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mueschke, Nicholas J. [Texas A and M Univ., College Station, TX (United States)

    2010-01-01

    Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipation and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. These results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.

  15. Analysis of turbulent transport and mixing in transitional Rayleigh–Taylor unstable flow using direct numerical simulation data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

    Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipationmore »and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. Thus, these results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.« less

  16. Determination of the Operating Envelope for a Direct Fired Fuel Cell Turbine Hybrid Using Hardware Based Simulation

    SciTech Connect (OSTI)

    David Tucker; Eric Liese; Randall Gemmen

    2009-02-10

    The operating range of a direct fired solid oxide fuel cell gas turbine (SOFC/GT) hybrid with bypass control of cathode airflow was determined using a hardware-based simulation facility designed and built by the U.S. Department of Energy, National Energy Technology Laboratory (NETL). Three methods of cathode airflow management using bypass valves in a hybrid power system were evaluated over the maximum range of operation. The cathode air flow was varied independently over the full range of operation of each bypass valve. Each operating point was taken at a steady state condition and was matched to the thermal, pressure and flow output of a corresponding fuel cell operation condition. Turbine electric load was also varied so that the maximum range of fuel cell operation could be studied, and a preliminary operating map could be made. Results are presented to show operating envelopes in terms of cathode air flow, fuel cell and turbine load, and compressor surge margin to be substantial.

  17. Process Simulation and Control Optimization of a Blast Furnace Using Classical Thermodynamics Combined to a Direct Search

    E-Print Network [OSTI]

    Martin, Alain

    consisting mainly of N2, CO, CO2, H2, and H2O. This is a consequence of the reduction of the iron ore volume methods, data-mining models, heat and mass balance models, and classical thermodynamic simulations-tune the simulation of the blast furnace. Optimal operating conditions and predicted output stream properties

  18. Comparison of direct numerical simulation of lean premixed methane-air flames with strained laminar flame calculations.

    SciTech Connect (OSTI)

    Chen, Jacqueline H.; Hawkes, Evatt R.

    2004-08-01

    Direct numerical simulation (DNS) with complex chemistry was used to study statistics of displacement and consumption speeds in turbulent lean premixed methane-air flames. The main focus of the study is an evaluation of the extent to which a turbulent flame in the thin reaction zones regime can be described by an ensemble of strained laminar flames. Conditional averages with respect to strain for displacement and consumption speeds are presented over a wide range of strain typically encountered in a turbulent flame, compared with previous studies that either made local pointwise comparisons or conditioned the data on small strain and curvature. The conditional averages for positive strains are compared with calculated data from two different canonical strained laminar configurations to determine which is the optimal representation of a laminar flame structure embedded in a turbulent flame: the reactant-to-product (R-to-P) configuration or the symmetric twin flame configuration. Displacement speed statistics are compared for the progress-variable isosurface of maximum reaction rate and an isosurface toward the fresh gases, which are relevant for both modeling and interpretation of experiment results. Displacement speeds in the inner reaction layer are found to agree very well with the laminar R-to-P calculations over a wide range of strain for higher Damkhler number conditions, well beyond the regime in which agreement was expected. For lower Damkhler numbers, a reduced response to strain is observed, consistent with previous studies and theoretical expectations. Compared with the inner layer, broader and shifted probability density functions (PDFs) of displacement speed were observed in the fresh gases, and the agreement with the R-to-P calculations deteriorated. Consumption speeds show a poorer agreement with strained laminar calculations, which is attributed to multidimensional effects and a more attenuated unsteady response to strain fluctuations; however, they also show less departure from the unstrained laminar value, suggesting that detailed modeling of this quantity may not be critical for the conditions considered. For all quantities investigated, including CO production, the R-to-P laminar configuration provides an improved description relative to the twin flame configuration, which predicts qualitatively incorrect trends and overestimates extinction.

  19. The Impacts of Indirect Soil Moisture Assimilation and Direct Surface Temperature and Humidity Assimilation on a Mesoscale Model Simulation of an Indian

    E-Print Network [OSTI]

    Niyogi, Dev

    Assimilation on a Mesoscale Model Simulation of an Indian Monsoon Depression VINODKUMAR AND A. CHANDRASEKAR-generation Pennsylvania State University­NCAR Mesoscale Model (MM5) simulation utilized the humidity and temperature

  20. IN-VEHICLE, HIGH-POWER ENERGY STORAGE SYSTEMS

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Properties of Uni-directionally Reinforced Hybrid Fiber Composites, " MS thesis in Engineering Mechanics, The Pennsylvania State University, Aug. 2013. * Ross, J. W., "On...

  1. Assessment of multi-decadal WRF-CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-07-01

    Multi-decadal simulations with the coupled WRF-CMAQ model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 21 years (1990–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analyses conducted by Gan et al. (2014) utilizingmore »observations (e.g. SURFRAD, CASTNET, IMPROVE and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF-CMAQ model is capable of replicating the trends well even through it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrenpancies found in the clear-sky diffuse SW radiation are likely due to several factors such as potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval methodology and aerosol semi-direct and/or indirect effects which cannot be readily isolated from the observed data.« less

  2. Directives Tools

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    Useful links and resources for Directives Writers, Directives Point of Contact (DPCs), Subject Matter Experts (SMEs), and Draft Directive Reviewers.

  3. Assessment of long-term WRF–CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-11-03

    Long-term simulations with the coupled WRF–CMAQ (Weather Research and Forecasting–Community Multi-scale Air Quality) model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 16 years (1995–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analysesmore »conducted by Gan et al. (2014a) utilizing observations (e.g., SURFRAD, CASTNET, IMPROVE, and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US, while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF–CMAQ model is capable of replicating the trends well even though it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrepancies found in the clear-sky diffuse SW radiation are likely due to several factors such as the potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval methodology, and aerosol semi-direct and/or indirect effects which cannot be readily isolated from the observed data.« less

  4. Examination of Granular Material Behavior in a Laminar-type Direct Simple Shear Device using Laboratory Validated Discrete Element Method Simulations 

    E-Print Network [OSTI]

    Bernhardt, Michelle Lee

    2013-08-29

    Simple shear testing is used to study a number of practical geotechnical prob­lems including: soil conditions directly below a loaded surface, adjacent to a driven pile shaft, soils deposited on a slightly inclined slope, ...

  5. Directives System

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1998-01-30

    The Department of Energy (DOE) Directives System is the means by which DOE policies, requirements, and responsibilities are developed and communicated throughout the Department. Directives are used to inform, direct, and guide employees in the performance of their jobs, and to enable employees to work effectively within the Department and with agencies, contractors, and the public. Cancels: DOE O 251.1, DOE M 251.1-1

  6. Direct Numerical Simulation of Cosmological Reionization /

    E-Print Network [OSTI]

    So, Geoffrey C.

    2013-01-01

    hydrogen reionization. Shown are projections of density, radiation energy density,hydrogen reionization. Shown are projections of density, radiation energy density,

  7. Direct Numerical Simulation and Large Eddy Simulation of Compressible Turbulence

    E-Print Network [OSTI]

    Erlebacher, Gordon

    of attention in the fluid dynamics community, owing perhaps to, the renewed interest in the de­ sign,b) Unfortunately, it is unlikely that the near future will bring about experiments detailed enough to confirm and in the definition of kinetic energy add a degree of complexity to the interpre­ tation of intermodal energy

  8. Directives Help

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    All DOE directives are available through this site. While it may seem overwhelming, given the number of documents, we have provided a number of ways in which you may get to the information you need.

  9. Numerical simulations for low energy nuclear reactions including...

    Office of Scientific and Technical Information (OSTI)

    Numerical simulations for low energy nuclear reactions including direct channels to validate statistical models Citation Details In-Document Search Title: Numerical simulations for...

  10. Direct electroplating on nonconductors

    SciTech Connect (OSTI)

    Weng, D.; Landau, U. [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Chemical Engineering

    1995-08-01

    Recently proposed processes for direct electroplating on nonconductive substrates offer numerous advantages. The industrial implementation of such processes is, however, hampered by lack of understanding. Presented here is a model for this class of processes based on three synergistic mechanisms: (i) stepwise propagation through the seed clusters that serve as sequentially activated microelectrodes, (ii) preferential accessibility to current of the sharp edge, and (iii) kinetics-based enhancement due to the fast propagation of an additive-free edge. The model has been computer simulated and verified by experiments of copper electroplating on nonconductive substrates.

  11. Chaos anti-synchronization in multiple time delay power systems

    E-Print Network [OSTI]

    Elman Shahverdiev

    2015-09-20

    We elucidate conditions for chaos anti-synchronization between two uni-directionally coupled multiple time delay power systems. The results are of some importance to prevent power black-out in the entire power grid.

  12. DRIVING DIRECTIONS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding Low-Cost2 DOE HQSiteo n n eDPFJ.D.DRIVING DIRECTIONS

  13. Direct Frisk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDirac ChargeSolarDirect

  14. GROUNDWATER REMEDIATION DESIGN USING SIMULATED

    E-Print Network [OSTI]

    Mays, Larry W.

    CHAPTER 8 GROUNDWATER REMEDIATION DESIGN USING SIMULATED ANNEALING Richard L. Skaggs Pacific? There has been an emergence in the use of combinatorial methods such as simulated annealing in groundwater for groundwater management applications. The algorithm incor- porates "directional search" and "memory

  15. Modeling and Optimization of PEMFC Systems and its Application to Direct Hydrogen Fuel Cell Vehicles

    E-Print Network [OSTI]

    Zhao, Hengbing; Burke, Andy

    2008-01-01

    operating conditions. Direct Hydrogen Fuel Cell System Modelconditions for a direct hydrogen fuel cell system Table 1simulation tool for hydrogen fuel cell vehicles, Journal of

  16. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-08-16

    The Order is the primary directive for administering the Department's directives Program. Cancels: DOE O 251.1A

  17. An Integrated Platform for Engine Performance Simulations and Optimization under Diesel Conditions

    Broader source: Energy.gov [DOE]

    The direct injection stochastic reactor model is capable of accurate simulation of combustion under diesel conditions and can also be used to simulate and test different fuels.

  18. 142 Los Alamos Science Number 29 2005 Direct Numerical

    E-Print Network [OSTI]

    Kurien, Susan

    142 Los Alamos Science Number 29 2005 Direct Numerical Simulations of Turbulence Data Generation visualization tools. Los Alamos scientists have been able to simulate flows of Reynolds numbers up to 105 subdomain of the 20483 turbulence simulation performed on the ASC Q machine at Los Alamos. The ASC Q machine

  19. Multiple direction vibration fixture

    DOE Patents [OSTI]

    Cericola, Fred (Albuquerque, NM); Doggett, James W. (Albuquerque, NM); Ernest, Terry L. (Albuquerque, NM); Priddy, Tommy G. (Rockville, MD)

    1991-01-01

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  20. Directives Quarterly Updates

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    Listings of new Justification Memoranda and new or revised Directives that have been posted to the DOE Directives, Delegations, and Requirements Portal. Updated quarterly.

  1. MESOSCALE SIMULATIONS OF POWDER COMPACTION

    SciTech Connect (OSTI)

    Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore CA 94551 (United States)

    2009-12-28

    Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

  2. Departmental Directives Program - DOE Directives, Delegations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DOE O 251.1C, Departmental Directives Program and Conforming Changes to DOE O 252.1, Technical Standards Program Redline of DOE O 251.1D - First Draft Comment Response Report...

  3. QUANTUM SIMULATION Coherent imaging spectroscopy of a

    E-Print Network [OSTI]

    Monroe, Christopher

    simulation. We use this method to determine the energy levels and interaction strengths of a fully connected quantum many-body system. Additionally, we directly measure the critical energy gap near a quantum phase transition. We expect this general technique to become a verification tool for quantum simulators once

  4. Direct/Indirect Costs

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28

    This chapter provides recommended categories for direct and indirect elements developed by the Committee for Cost Methods Development (CCMD) and describes various estimating techniques for direct and indirect costs.

  5. Directives System Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1998-01-30

    This Manual provides detailed requirements to supplement DOE O 251.1A, Directives System, dated 1-30-98.

  6. Two dimensional control of metamaterial parameters for radiation directivity

    E-Print Network [OSTI]

    Foltz, Eleanor R. (Eleanor Ruth)

    2006-01-01

    This work examines the feasibility of using metamaterials to direct radiation. The limits of required index of refraction and the required material depth are explored using MATLAB simulations. A wedge of connected S-shape ...

  7. Directional recoil rates for WIMP direct detection

    SciTech Connect (OSTI)

    Alenazi, Moqbil S.; Gondolo, Paolo [Department of Physics, University of Utah, 115 S 1400 E Rm 201, Salt Lake City, Utah 84112-0830 (United States)

    2008-02-15

    New techniques for the laboratory direct detection of dark matter weakly interacting massive particles (WIMPs) are sensitive to the recoil direction of the struck nuclei. We compute and compare the directional recoil rates dR/dcos{theta} (where {theta} is the angle measured from a reference direction in the sky) for several WIMP velocity distributions including the standard dark halo and anisotropic models such as Sikivie's late-infall halo model and logarithmic-ellipsoidal models. Since some detectors may be unable to distinguish the beginning of the recoil track from its end (lack of head-tail discrimination), we introduce a folded directional recoil rate dR/d|cos{theta}|, where |cos{theta}| does not distinguish the head from the tail of the track. We compute the CS{sub 2} and CF{sub 4} exposures required to distinguish a signal from an isotropic background noise, and find that dR/d|cos{theta}| is effective for the standard dark halo and some but not all anisotropic models.

  8. Directives Tools - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinumDirections New
Directives &

  9. Directives - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections &Directions

  10. Building Performance Simulation

    E-Print Network [OSTI]

    Hong, Tianzhen

    2014-01-01

    Y (2008). DeST—An integrated building simulation toolkit,Part ? : Fundamentals. Building Simulation, 1: 95 ? 110.Y (2008). DeST—An integrated building simulation toolkit,

  11. Discrete Fracture Reservoir Simulation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Discrete Fracture Reservoir Simulation Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, fractured reservoir modeling software developed by NETL's Geological and...

  12. Direct numerical simulation of turbulent Taylor–Couette flow

    E-Print Network [OSTI]

    2007-08-23

    Brindley (1984) proposed a mathematical model by partitioning the flow into interior. (Taylor ... A comprehensive verification for several parameters was conducted, ... The cylinder axis is aligned with the z-axis of the coordinate system

  13. Turbulent Supersonic Channel Flow: Direct Numerical Simulation and Modeling

    E-Print Network [OSTI]

    Heinz, Stefan

    modeling: the turbulence frequency production mechanism, wall damping effects on turbulence model frequency production mechanisms and wall damping effects may be explained very well on the basis, Chik w = wall viscosity = kinematic viscosity, = T = turbulent kinematic viscosity, Ck d = pressure

  14. Direct Numerical Simulation of Solid Deformation During Dendritic Solidification

    E-Print Network [OSTI]

    Beckermann, Christoph

    solidification is a common phe- nomenon in metal casting and can lead to defects such as hot tears, macro is caused by external forces, for example through the rolls in continuous casting, mold wall movement of the mush can lead to numerous defects in a solidified casting, including hot tears, macrosegregation

  15. Direct Numerical Simulation of Compressible, Turbulent Flow | Argonne

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileep SinghLeadership Computing

  16. Direct Numerical Simulations and Robust Predictions of Cloud Cavitation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileep SinghLeadership

  17. Numerical simulations for low energy nuclear reactions including direct

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech Connect Nanomechanical switchFlue Gas StreamsConnectArticle)reversalradiation

  18. Numerical simulations for low energy nuclear reactions including direct

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTech Connect Nanomechanical switchFlue Gas

  19. Multi-Phase Flow: Direct Numerical Simulation Igor Bolotnov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJessework usesof Energy Moving Forward to Address Nuclear3-000 Multi-Phase

  20. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2014-10-16

    To establish directives as the primary means to set, communicate, and institutionalize policies, requirements, responsibilities, and procedures for Departmental elements and contractors.

  1. Directives System Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-16

    This Manual provides detailed requirements to supplement DOE O 251.1, which establishes requirements for the development, coordination, and sunset review of DOE directives.

  2. Direct Photons at RHIC

    E-Print Network [OSTI]

    Klaus Reygers; for the PHENIX Collaboration

    2009-08-17

    A brief overview of direct-photon measurements in p+p and Au+Au collisions at sqrt(s_NN) = 200 GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is given. Direct-photon yields for pT > 4 GeV/c and photon-hadron azimuthal correlations were determined with the aid of an electromagnetic calorimeter. By detecting e+e- pairs from the internal conversion of virtual photons direct-photon yields were measured between 1 photons from a quark-gluon plasma (QGP) are expected to contribute significantly to the total direct-photon yield in this range.

  3. Cancellation of Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-01-26

    Effective immediately the following Department of Energy directive is canceled. DOE M 452.2-2, Nuclear Explosive Safety Evaluation Processes, dated 04-14-2009.

  4. Direct-fired biomass

    SciTech Connect (OSTI)

    None, None

    2009-01-18

    The direct-fired biomass section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  5. A Direct Measure of Entrainment DAVID M. ROMPS

    E-Print Network [OSTI]

    Romps, David M.

    A Direct Measure of Entrainment DAVID M. ROMPS Harvard University, Cambridge, Massachusetts for directly measuring convective entrainment and detrainment in a cloud- resolving simulation. This technique is used to quantify the errors in the entrainment and detrainment esti- mates obtained using the standard

  6. Departmental Directives System

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1983-04-07

    The order establishes the directives system to be used for publishing permanent and temporary directives issued by DOE Headquarters and addressed to Headquarters and/or field elements. Chg 1 dated 3-14-85. Cancels DOE 1321.1A.

  7. Directives Quarterly Updates - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's

  8. Directives Templates - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections

  9. Plasma Simulation Program

    SciTech Connect (OSTI)

    Greenwald, Martin

    2011-10-04

    Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. [1]. Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a critical impediment to successful operation of machines like ITER. If disruptions prove unable to be avoided, their associated dynamics and effects will be addressed in the next phase of the FSP.

  10. Peptide partitioning properties from direct insertion studies

    SciTech Connect (OSTI)

    Ulmschneider, Martin [University of Oxford; Smith, Jeremy C [ORNL; Ulmschneider, Jakob [University of Heidelberg

    2010-06-01

    Partitioning properties of polypeptides are at the heart of biological membrane phenomena and their precise quantification is vital for ab-initio structure prediction and the accurate simulation of membrane protein folding and function. Recently the cellular translocon machinery has been employed to determine membrane insertion propensities and transfer energetics for a series of polyleucine segments embedded in a carrier sequence. We show here that the insertion propensity, pathway, and transfer energetics into synthetic POPC bilayers can be fully described by direct atomistic peptide partitioning simulations. The insertion probability as a function of peptide length follows two-state Boltzmann statistics, in agreement with the experiments. The simulations expose a systematic offset between translocon-mediated and direct insertion free energies. Compared to the experiment the insertion threshold is shifted toward shorter peptides by 2 leucine residues. The simulations reveal many hitherto unknown atomic-resolution details about the partitioning process and promise to provide a powerful tool for urgently needed calibration of lipid parameters to match experimentally observed peptide transfer energies.

  11. dfield8 Direction Fields

    E-Print Network [OSTI]

    2010-08-05

    dfield8 Direction Fields. • The routine dfield8 is already loaded on all ITaP machines as standard software. To access MAtlAB from any ITaP machine: Start

  12. Art Directable Tornadoes 

    E-Print Network [OSTI]

    Dwivedi, Ravindra

    2011-08-08

    ......................................................................... 25 2. Directional Force ........................................................... 26 3. Vortex Force .................................................................. 26 4. Lattice... ................................................................... 7 7 Tornado in its rope stage before disappearing ........................................... 9 8 Fire vortex and Waterspout ........................................................................ 10 9 Landspout and Gustnado...

  13. Direct nuclear pumped laser

    DOE Patents [OSTI]

    Miley, George H. (Champagne, IL); Wells, William E. (Urbana, IL); DeYoung, Russell J. (Hampton, VA)

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  14. Direct from CDC's Environmental

    E-Print Network [OSTI]

    Direct from CDC's Environmental Health Services Branch CAPT Mark D. Miller, R.S., M.P.H. The Role control/ handwashing, solid waste disposal, vector control, general safety, sewage disposal, and adequate

  15. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-08-13

    The order establishes directives as the primary means to set, communicate, and institutionalize policies, requirements, responsibilities, and procedures for Departmental elements and contractors. The second draft is being submitted for review owing to extensive revisions to the first draft.

  16. Refrigerant directly cooled capacitors

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN); Seiber, Larry E. (Oak Ridge, TN); Marlino, Laura D. (Oak Ridge, TN); Ayers, Curtis W. (Kingston, TN)

    2007-09-11

    The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

  17. Understanding Manufacturing Systems with a Learning Historian for User-Directed Experimentation

    E-Print Network [OSTI]

    Herrmann, Jeffrey W.

    a wide variety of important problems in manufacturing and other complex systems. In addition, simulation1 Understanding Manufacturing Systems with a Learning Historian for User-Directed Experimentation to improve user-directed experimentation with discrete event simulation models of manufacturing systems

  18. Understanding Manufacturing Systems with a Learning Historian for UserDirected Experimentation

    E-Print Network [OSTI]

    Golbeck, Jennifer

    a wide variety of important problems in manufacturing and other complex systems. In addition, simulation1 Understanding Manufacturing Systems with a Learning Historian for User­Directed Experimentation to improve user­directed experimentation with discrete event simulation models of manufacturing systems

  19. Mesoscale Simulations of Power Compaction

    SciTech Connect (OSTI)

    Lomov, I; Fujino, D; Antoun, T; Liu, B

    2009-08-06

    Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.

  20. Broken symmetries and directed collective energy transport

    E-Print Network [OSTI]

    S. Flach; Y. Zolotaryuk; A. E. Miroshnichenko; M. V. Fistul

    2001-10-09

    We study the appearance of directed energy current in homogeneous spatially extended systems coupled to a heat bath in the presence of an external ac field E(t). The systems are described by nonlinear field equations. By making use of a symmetry analysis we predict the right choice of E(t) and obtain directed energy transport for systems with a nonzero topological charge Q. We demonstrate that the symmetry properties of motion of topological solitons (kinks and antikinks) are equivalent to the ones for the energy current. Numerical simulations confirm the predictions of the symmetry analysis and, moreover, show that the directed energy current drastically increases as the dissipation parameter $\\alpha$ reduces. Our results generalize recent rigorous theories of currents generated by broken time-space symmetries to the case of interacting many-particle systems.

  1. Direct Photons at RHIC

    E-Print Network [OSTI]

    G. David; for the PHENIX Collaboration

    2008-10-21

    Direct photons are ideal tools to investigate kinematical and thermodynamical conditions of heavy ion collisions since they are emitted from all stages of the collision and once produced they leave the interaction region without further modification by the medium. The PHENIX experiment at RHIC has measured direct photon production in p+p and Au+Au collisions at 200 GeV over a wide transverse momentum ($p_T$) range. The $p$ + $p$ measurements allow a fundamental test of QCD, and serve as a baseline when we try to disentangle more complex mechanisms producing high $p_T$ direct photons in Au+Au. As for thermal photons in Au+Au we overcome the difficulties due to the large background from hadronic decays by measuring "almost real" virtual photons which appear as low invariant mass $e^+e^-$ pairs: a significant excess of direct photons is measured above the above next-to-leading order perturbative quantum chromodynamics calculations. Additional insights on the origin of direct photons can be gained with the study of the azimuthal anisotropy which benefits from the increased statistics and reaction plane resolution achieved in RHIC Year-7 data.

  2. Direct conversion technology

    SciTech Connect (OSTI)

    Massier, P.F.; Back, L.H.; Ryan, M.A.; Fabris, G.

    1992-01-07

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. This report contains progress of research on the Alkali Metal Thermal-to-Electric Converter (AMTEC) and on the Two-Phase Liquid-Metal MHD Electrical Generator (LMMHD) for the period January 1, 1991 through December 31, 1991. Research on AMTEC and on LMMHD was initiated during October 1987. Reports prepared on previous occasions (Refs. 1--5) contain descriptive and performance discussions of the following direct conversion concepts: thermoelectric, pyroelectric, thermionic, thermophotovoltaic, thermoacoustic, thermomagnetic, thermoelastic (Nitionol heat engine); and also, more complete descriptive discussions of AMTEC and LMMHD systems.

  3. Highly directional thermal emitter

    DOE Patents [OSTI]

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  4. Development of directional capabilities to an ultradeep water dynamic kill simulator and simulations runs 

    E-Print Network [OSTI]

    Meier, Hector Ulysses

    2005-11-01

    The world is dependent on the production of oil and gas, and every day the demand increases. Technologies have to keep up with the demand of this resource to keep the world running. Since hydrocarbons are finite and will ...

  5. Directed Quantum Chaos

    SciTech Connect (OSTI)

    Efetov, K.B. [Max-Planck Institut fuer Physik komplexer Systeme, Heisenbergstrasse 1, 70569 Stuttgart (Germany)] [Max-Planck Institut fuer Physik komplexer Systeme, Heisenbergstrasse 1, 70569 Stuttgart (Germany); [L.D. Landau Institute for Theoretical Physics, Moscow (Russia)

    1997-07-01

    Quantum disordered problems with a direction (imaginary vector potential) are discussed and mapped onto a supermatrix {sigma} model. It is argued that the 0D version of the {sigma} model may describe a broad class of phenomena that can be called directed quantum chaos. It is demonstrated by explicit calculations that these problems are equivalent to those of random asymmetric or non-Hermitian matrices. A joint probability of complex eigenvalues is obtained. The fraction of states with real eigenvalues proves to be always finite for time reversal invariant systems. {copyright} {ital 1997} {ital The American Physical Society}

  6. Direct Conversion Technology

    SciTech Connect (OSTI)

    Back, L.H.; Fabris, G.; Ryan, M.A.

    1992-07-01

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)

  7. Directed Relativistic Blast Wave

    E-Print Network [OSTI]

    Andrei Gruzinov

    2007-04-23

    A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion momentum close to the explosion energy, produces a blast wave with a universal intermediate asymptotic -- a selfsimilar directed ultra-relativistic blast wave. This universality might be of interest for the astrophysics of gamma-ray burst afterglows.

  8. Directions & Maps

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections & Maps Directions

  9. Directions to Berkeley Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections & MapsDirections

  10. High Temperature 300°C Directional Drilling System

    SciTech Connect (OSTI)

    Chatterjee, Kamalesh; Aaron, Dick; Macpherson, John

    2015-07-31

    Many countries around the world, including the USA, have untapped geothermal energy potential. Enhanced Geothermal Systems (EGS) technology is needed to economically utilize this resource. Temperatures in some EGS reservoirs can exceed 300°C. To effectively utilize EGS resources, an array of injector and production wells must be accurately placed in the formation fracture network. This requires a high temperature directional drilling system. Most commercial services for directional drilling systems are rated for 175°C while geothermal wells require operation at much higher temperatures. Two U.S. Department of Energy (DOE) Geothermal Technologies Program (GTP) projects have been initiated to develop a 300°C capable directional drilling system, the first developing a drill bit, directional motor, and drilling fluid, and the second adding navigation and telemetry systems. This report is for the first project, “High Temperature 300°C Directional Drilling System, including drill bit, directional motor and drilling fluid, for enhanced geothermal systems,” award number DE-EE0002782. The drilling system consists of a drill bit, a directional motor, and drilling fluid. The DOE deliverables are three prototype drilling systems. We have developed three drilling motors; we have developed four roller-cone and five Kymera® bits; and finally, we have developed a 300°C stable drilling fluid, along with a lubricant additive for the metal-to-metal motor. Metal-to-metal directional motors require coatings to the rotor and stator for wear and corrosion resistance, and this coating research has been a significant part of the project. The drill bits performed well in the drill bit simulator test, and the complete drilling system has been tested drilling granite at Baker Hughes’ Experimental Test Facility in Oklahoma. The metal-to-metal motor was additionally subjected to a flow loop test in Baker Hughes’ Celle Technology Center in Germany, where it ran for more than 100 hours.

  11. Oil spreading in surface waters with an ice cover

    SciTech Connect (OSTI)

    Yapa, P.D.; Weerasuriya, S.A.; Belaskas, D.P.; Chowdhury, T.

    1993-02-01

    A study of oil spreading in surface waters in the presence of a floating ice cover is presented. The ice can be solid or fragmented. Both axi-symmetrical and uni-directional spreading are studied. The report describes the analytical and numerical model development, the experimental set-up, results from the laboratory experiments, and their comparison with the derived theory and the numerical simulation. To analyze the spreading of oil under solid ice, new equations are derived. These equations consider gravity (buoyancy) - inertia phase, gravity (buoyancy) - viscous phase, and the termination of spreading during the buoyancy - surface tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to termination of spreading is presented. The emphasis of the study is on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase.

  12. Analysis of Cold Air Distribution System in an Office Building by the Numerical Simulation Method 

    E-Print Network [OSTI]

    Jian, Y.; Li, D.; Xu, H.; Ma, X.

    2006-01-01

    Numerical simulation is carried out in this paper to calculate indoor air patterns, which include angles of inlet direction and induced ratios in a typical official room. According to the simulation results, the indoor air distribution and indoor...

  13. Directed Regression Stanford University

    E-Print Network [OSTI]

    Van Roy, Ben

    Directed Regression Yi-hao Kao Stanford University Stanford, CA 94305 yihaokao Stanford, CA 94305 xyan@stanford.edu Abstract When used to guide decisions, linear regression analysis typically involves esti- mation of regression coefficients via ordinary least squares and their subsequent

  14. Deregulation Direct Access

    E-Print Network [OSTI]

    Kammen, Daniel M.

    AB 1890 AB1X Aggregator Blue Book CEC CPUC CTC Deregulation Direct Access Divestiture DWR EOB EPAct an initiative on the ballot in response to the energy crisis. www.ftcr.org ESPs that sell electricity generated of peak demand. Investor Owned Utility. A private electric utility (owned by shareholders) regulated

  15. Directed Diffusion Fabio Silva

    E-Print Network [OSTI]

    Heidemann, John

    nodes can cache, or transform data, and may direct interests based on previously cached data (Section 3 University of Southern California Los Angeles, CA, USA 90089 ¶ Computer Science Department University of California, Los Angeles Los Angeles, CA, USA 90095 {fabio,johnh,govindan,estrin}@isi.edu February 10, 2004 1

  16. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-08-12

    The following directives are extended until 8-12-05: DOE N 205.2, Foreign National Access to DOE Cyber Security Systems, dated 11-1-99 and DOE N 205.3, Password Generation, Protection, and Use, dated 11-23-99. No cancellations.

  17. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2003-02-24

    This Notice extends the following directives until 2/16/04: DOE N 205.2, Foreign National Access to DOE Cyber Systems, and DOE N 205.3, Password Generation, Protection, and Use, dated 11/23/99-7/1/00.

  18. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-02-12

    The following directives are extended until 8-12-04. DOE N 205.2, Foreign National Access to DOE Cyber Systems, dated 11/1/99. DOE N 205.3, Password Generation, Protection, and Use, dated 11/23/99.

  19. Direct fired heat exchanger

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  20. Direct from CDC's Environmental

    E-Print Network [OSTI]

    Direct from CDC's Environmental Health Services Branch CAPT Daniel M. Harper, M.P.H. A Diverse Environmental Public Health Workforce to Meet the Diverse Environmental Health Challenges on environmental health and to build part nerships in the profession. In pursuit of these goals, we will feature

  1. Direct from CDC's Environmental

    E-Print Network [OSTI]

    Direct from CDC's Environmental Health Services Branch Brian Hubbard, M.P.H. Editor the Environmental Health Services Branch (EHSB) of the Centers for Disease Con trol and Prevention (CDC) in every environmental health programs and professionals to antici pate, identify, and respond to adverse envi ronmental

  2. Direct from CDC's Environmental

    E-Print Network [OSTI]

    Direct from CDC's Environmental Health Services Branch Daneen Farrow Collier, M.S.P.H. Editor's note: NEHA strives to pro vide up-to-date and relevant informa tion on environmental health the Environmental Health Services Branch (EHSB) of the Centers for Disease Control and Pre vention (CDC) in every

  3. Direct from CDC's Environmental

    E-Print Network [OSTI]

    Direct from CDC's Environmental Health Services Branch CAPT John Sarisky, R.S., M.P.H. Developing Environmental Public Health Leadership Editor's note: NEHA strives to provide up to of these goals, we will feature a column from the Environmental Health Services Branch (EHSB) of the Centers

  4. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    SciTech Connect (OSTI)

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  5. Implementing Feedback Control on a Novel Proximity Operations Simulation Platform 

    E-Print Network [OSTI]

    Aures-Cavalieri, Kurt Dale

    2012-07-16

    Recently, The Land, Air and Space Robotics (LASR) Laboratory has demonstrated a state-of-the-art proximity operations test bed that will revolutionize the concept of portable space systems simulation. The Holonomic Omni-directional Motion Emulation...

  6. Numerical Simulation Study on Transpired Solar Air Collector 

    E-Print Network [OSTI]

    Wang, C.; Guan, Z.; Zhao, X.; Wang, D.

    2006-01-01

    The unglazed transpired solar air collector is now a well-recognized solar air heater for heating outside air directly. In this article, researchers introduced numerical simulation tools into the solar air collector research area, analyzed...

  7. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett Lee; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-09-19

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  8. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2007-02-27

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  9. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-07-11

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  10. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2006-10-10

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  11. Direct hydrocarbon fuel cells

    DOE Patents [OSTI]

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  12. Lattice Simulations using OpenACC compilers

    E-Print Network [OSTI]

    Pushan Majumdar

    2013-11-12

    OpenACC compilers allow one to use Graphics Processing Units without having to write explicit CUDA codes. Programs can be modified incrementally using OpenMP like directives which causes the compiler to generate CUDA kernels to be run on the GPUs. In this article we look at the performance gain in lattice simulations with dynamical fermions using OpenACC compilers.

  13. Directional emission of stadium-shaped micro-lasers

    E-Print Network [OSTI]

    M. Lebental; J. -S. Lauret; J. Zyss; C. Schmit; E. Bogomolny

    2006-09-01

    The far-field emission of two dimensional (2D) stadium-shaped dielectric cavities is investigated. Micro-lasers with such shape present a highly directional emission. We provide experimental evidence of the dependance of the emission directionality on the shape of the stadium, in good agreement with ray numerical simulations. We develop a simple geometrical optics model which permits to explain analytically main observed features. Wave numerical calculations confirm the results.

  14. Energy Distribution of Nanoflares in Three-Dimensional Simulations of

    E-Print Network [OSTI]

    Ng, Chung-Sang

    Energy Distribution of Nanoflares in Three-Dimensional Simulations of Coronal Heating Chung-Sang Ng of the energy distribution of solar flares, there have not been many results based on large-scale three-dimensional direct simulations due to obvious numerical difficulties. We will present energy distributions and other

  15. Directions_Crossroads_Facilities

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinumDirections New


  16. Omni-directional railguns

    DOE Patents [OSTI]

    Shahinpoor, M.

    1995-07-25

    A device is disclosed for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire. 4 figs.

  17. Omni-directional railguns

    DOE Patents [OSTI]

    Shahinpoor, Mohsen (9521 Avenida Del Oso NE., Albuquerque, NM 87111)

    1995-01-01

    A device for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.

  18. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-03-18

    The following directives are extended until 3-18-06: DOE N 205.8, Cyber Security Requirements for Wireless Devices and Information Systems, dated 2-11-04; DOE N 205.9, Certification and Accreditation Process for Information Systems Including National Security Systems, dated 02-19-04; DOE N 205.10, Cyber Security Requirements for Risk Management, dated 02-19-04; DOE N 205.11, Security Requirements for Remote Access to DOE and Applicable Contractor Information Technology Systems, dated 2-19-04. DOE N 205.12, Clearing, Sanitizing, and Destroying Information System Storage Media, Memory Devices, and Other Related Hardware, dated 2-19-04.

  19. Buckman Direct Diversion Project

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransen PlasmaEnergy, science,Buckman Direct Diversion Project

  20. Direct Federal Financial

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming963 1.969 1.979Coal4Cubic Feet)Cubic1992Thousand9)%YearD e sDirect

  1. Directives Points of Contact

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections

  2. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's home page

  3. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's home

  4. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's

  5. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's

  6. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's home page

  7. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's home page

  8. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management's home page

  9. Non Nuclear NTR Environmental Simulator

    SciTech Connect (OSTI)

    Emrich, William J. Jr. [NASA Marshall Space Flight Center, M.S. XD21, Huntsville, Alabama 35812 (United States)

    2006-01-20

    Nuclear Thermal Rockets or NTR's have been suggested as a propulsion system option for vehicles traveling to the moon or Mars. These engines are capable of providing high thrust at specific impulses at least twice that of today's best chemical engines. The performance constraints on these engines are mainly the result of temperature limitations on the fuel coupled with a limited ability to withstand chemical attack by the hot hydrogen propellant. To operate at maximum efficiency, fuel forms are desired which can withstand the extremely hot, hostile environment characteristic of NTR operation for at least several hours. The simulation of such an environment would require an experimental device which could simultaneously approximate the power, flow, and temperature conditions which a nuclear fuel element (or partial element) would encounter during NTR operation. Such a simulation would allow detailed studies of the fuel behavior and hydrogen flow characteristics under reactor like conditions to be performed. The goal of these simulations would be directed toward expanding the performance envelope of NTR engines over that which was demonstrated during the Rover and NERVA nuclear rocket programs of the 1970's. Current planning calls for such a simulator to be constructed at the Marshall Space Flight Center over the coming year, and it is anticipated that it will be used in the future to evaluate a wide variety of fuel element designs and the materials of which they are constructed. This present work addresses the initial experimental objectives of the NTR simulator with regard to reproducing the fuel degradation patterns previously observed during the NERVA testing.

  10. Remote direct memory access

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  11. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  12. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  13. SIMULATING EVOLUTION OF TECHNOLOGY

    E-Print Network [OSTI]

    SIMULATING EVOLUTION OF TECHNOLOGY: AN AID TO ENERGY POLICY ANALYSIS A CASE STUDY OF STRATEGIES Approval Name: John Nyboer Degree: Doctor of Philosophy Title of Thesis: Simulating Evolution of Technology

  14. Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry: Spray Simulations

    SciTech Connect (OSTI)

    Rutland, Christopher J.

    2009-04-26

    The Terascale High-Fidelity Simulations of Turbulent Combustion (TSTC) project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of the approach is direct numerical simulation (DNS) featuring the highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. Under this component of the TSTC program the simulation code named S3D, developed and shared with coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for turbulent liquid fuel spray dynamics. Major accomplishments include improved fundamental understanding of mixing and auto-ignition in multi-phase turbulent reactant mixtures and turbulent fuel injection spray jets.

  15. A Transactional Architecture for Simulation Department of Computer Science

    E-Print Network [OSTI]

    Kent, University of

    directly with each other, but interact through the medium provided by their environment. Agents place typically be characterised as a series of queries and updates to its environment--a "transactional" pattern directly as channels or method calls. As more complex simulations were constructed, the lack of structure

  16. Numerical Simulations of MHD Turbulence in Accretion Disks

    E-Print Network [OSTI]

    Steven A. Balbus; John F. Hawley

    2002-03-20

    We review numerical simulations of MHD turbulence. The last decade has witnessed fundamental advances both in the technical capabilities of direct numerical simulation, and in our understanding of key physical processes. Magnetic fields tap directly into the free energy sources in a sufficiently ionized gas. The result is that adverse angular velocity and adverse temperature gradients, not the classical angular momentum and entropy gradients, destabilize laminar and stratified flow. This has profound consequences for astrophysical accretion flows, and has opened the door to a new era of numerical simulation experiments.}

  17. Directed light fabrication

    SciTech Connect (OSTI)

    Lewis, G.K.; Nemec, R.; Milewski, J.; Thoma, D.J.; Cremers, D.; Barbe, M.

    1994-09-01

    Directed Light Fabrication (DLF) is a rapid prototyping process being developed at Los Alamos National Laboratory to fabricate metal components. This is done by fusing gas delivered metal powder particles in the focal zone of a laser beam that is, programmed to move along or across the part cross section. Fully dense metal is built up a layer at a time to form the desired part represented by a 3 dimensional solid model from CAD software. Machine ``tool paths`` are created from the solid model that command the movement and processing parameters specific to the DLF process so that the part can be built one layer at a time. The result is a fully dense, near net shape metal part that solidifies under rapid solidification conditions.

  18. Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects

    E-Print Network [OSTI]

    1 Manufacturing Defects Common to Composite Wind Turbine Blades: Effects of Defects Jared W. Nelson The Blade Reliability Collaborative has been formed to perform comprehensive studies to improve wind turbine uni-directional wind turbine fiber-reinforced composite material with an epoxy resin were utilized

  19. RESEARCH ARTICLE In situ LIF temperature measurements in aqueous ammonium

    E-Print Network [OSTI]

    Koochesfahani, Manoochehr M.

    of the temperature field using laser-induced fluorescence in a study of bottom-chilled uni-directional solidification the significant spatial and temporal variations of laser sheet intensity field due to refractive index variations, Iran Present Address: C. L. Lum BD Medical, Franklin Lakes, NJ 07417, USA 123 Exp Fluids (2010) 48

  20. Photo-driven Molecular Wankel Engine B$_{13}^+$

    E-Print Network [OSTI]

    Zhang, Jin; Sparta, Manuel; Alexandrova, Anastassia N

    2012-01-01

    We report a molecular Wankel motor, the dual-ring structure B13+, driven by circularly-polarized infrared electromagnetic radiation, under which a guided uni-directional rotation of the outer ring is achieved with rotational frequency of the order of 300 MHz.

  1. Software interoperability for energy simulation

    E-Print Network [OSTI]

    Hitchcock, Robert J.

    2002-01-01

    Tools,” in Building Energy Simulation User News, Vol. 22,Interoperability for Energy Simulation Robert J. Hitchcock,Interoperability for Energy Simulation Robert J. Hitchcock,

  2. LATEX TikZposter Simulation of two-phase flow for

    E-Print Network [OSTI]

    Ábrahám, Erika

    LATEX TikZposter Simulation of two-phase flow for direct steam-generating solar thermal power Aachen University Simulation of two-phase flow for direct steam-generating solar thermal power plants University Concentrating solar thermal power plants Concentrating solar thermal power (CSP) plants

  3. Quasi-spherical direct drive fusion.

    SciTech Connect (OSTI)

    VanDevender, J. Pace; Abbott, Lucas M.; Langston, William L.; McDaniel, Dillon Heirman; Nash, Thomas J.; Roderick, Norman Frederick; Silva, M.

    2007-01-01

    The authors present designs of quasi-spherical direction drive z-pinch loads for machines such as ZR at 28 MA load current with a 150 ns implosion time (QSDDI). A double shell system for ZR has produced a 2D simulated yield of 12 MJ, but the drive for this system on ZR has essentially no margin. A double shell system for a 56 MA driver at 150 ns implosion has produced a simulated yield of 130 MJ with considerable margin in attaining the necessary temperature and density-radius product for ignition. They also represent designs for a magnetically insulated current amplifier, (MICA), that modify the attainable ZR load current to 36 MA with a 28 ns rise time. The faster pulse provided by a MICA makes it possible to drive quasi-spherical single shell implosions (QSDD2). They present results from 1D LASNEX and 2D MACH2 simulations of promising low-adiabat cryogenic QSDD2 capsules and 1D LASNEX results of high-adiabat cryogenic QSDD2 capsules.

  4. Bioenergy Technologies Office New Directions

    Broader source: Energy.gov [DOE]

    New Directions and New Business Opportunities for BETO Valerie Reed, Acting Director, BETO, U.S. Department of Energy

  5. MAPPING HVAC SYSTEMS FOR SIMULATION IN ENERGYPLUS

    E-Print Network [OSTI]

    Basarkar, Mangesh

    2013-01-01

    Semi-Automated Building Energy Performance Simulation, in:Simulation of Energy Performance, in: Building Simulation

  6. Modeling the Direct and Indirect Effects of Atmospheric Aerosols on Tropical Cyclones 

    E-Print Network [OSTI]

    Lee, Keun-Hee

    2012-02-14

    The direct and indirect effects of aerosols on the hurricane ‘Katrina’ have been investigated using the WRF model with a two-moment bulk microphysical scheme and modified Goddard shortwave radiation scheme. Simulations of the hurricane ‘Katrina...

  7. FY 2011 Third Quarter Report Estimate of Historical Aerosol Direct and Indirect Effects

    SciTech Connect (OSTI)

    Koch, D

    2011-06-22

    The global and annual mean aerosol direct and indirect effects estimated from Community Earth System Model (CESM) simulations are -0.06 W m-2 and -1.39 W m-2, respectively.

  8. UTILITY OF MECHANISTIC MODELS FOR DIRECTING ADVANCED SEPARATIONS RESEARCH & DEVELOPMENT ACTIVITIES: Electrochemically Modulated Separation Example

    SciTech Connect (OSTI)

    Schwantes, Jon M.

    2009-06-01

    The objective for this work was to demonstrate the utility of mechanistic computer models designed to simulate actinide behavior for use in efficiently and effectively directing advanced laboratory R&D activities associated with developing advanced separations methods.

  9. European Lean Gasoline Direct Injection Vehicle Benchmark

    SciTech Connect (OSTI)

    Chambon, Paul H; Huff, Shean P; Edwards, Kevin Dean; Norman, Kevin M; Prikhodko, Vitaly Y; Thomas, John F

    2011-01-01

    Lean Gasoline Direct Injection (LGDI) combustion is a promising technical path for achieving significant improvements in fuel efficiency while meeting future emissions requirements. Though Stoichiometric Gasoline Direct Injection (SGDI) technology is commercially available in a few vehicles on the American market, LGDI vehicles are not, but can be found in Europe. Oak Ridge National Laboratory (ORNL) obtained a European BMW 1-series fitted with a 2.0l LGDI engine. The vehicle was instrumented and commissioned on a chassis dynamometer. The engine and after-treatment performance and emissions were characterized over US drive cycles (Federal Test Procedure (FTP), the Highway Fuel Economy Test (HFET), and US06 Supplemental Federal Test Procedure (US06)) and steady state mappings. The vehicle micro hybrid features (engine stop-start and intelligent alternator) were benchmarked as well during the course of that study. The data was analyzed to quantify the benefits and drawbacks of the lean gasoline direct injection and micro hybrid technologies from a fuel economy and emissions perspectives with respect to the US market. Additionally that data will be formatted to develop, substantiate, and exercise vehicle simulations with conventional and advanced powertrains.

  10. A Scalable Parallel Monte Carlo Method for Free Energy Simulations of Molecular Systems

    E-Print Network [OSTI]

    Chan, Derek Y C

    A Scalable Parallel Monte Carlo Method for Free Energy Simulations of Molecular Systems MALEK O for problems where the energy dominates the entropy. An example is parallel tempering, in which simulations the free energy of the system as a direct output of the simulation. Traditional Metropolis MC samples phase

  11. A method to bridge the gap between affordance formalisation and visual simulation in virtual environment

    E-Print Network [OSTI]

    Frénod, Emmanuel

    of the emergence of interaction between a human or animal agent and some relevant patterns of sensorial informationA method to bridge the gap between affordance formalisation and visual simulation in virtual to a concrete simulation of the model within a Virtual Environment. This simulation makes the direct observation

  12. Simulation Calibration Autotune Calibration

    E-Print Network [OSTI]

    Wang, Xiaorui "Ray"

    Calibration as Search #12;· EnergyPlus is a desktop app · Writes files during a simulation · Use RAMdisk (mm:ss) Data Size EnergyPlus Simulations 16 18:14 5 GB 64 32 18:19 11 GB 128 64 18:34 22 GB 256 128 18 ... #12;· EnergyPlus ­ 2-10 mins for an annual simulation !- ALL OBJECTS IN CLASS Version, 7.0; !- Version

  13. Ferrocyanide waste simulant characterization

    SciTech Connect (OSTI)

    Jeppson, D.W.; Wong, J.J.

    1993-01-01

    Ferrocyanide waste simulants were prepared and characterized to help assess safety concerns associated with the ferrocyanide sludges stored in underground single-shell waste tanks at the Hanford Site. Simulants were prepared to represent the variety of ferrocyanide sludges stored in the storage tanks. Physical properties, chemical compositions, and thermodynamic properties of the simulants were determined. The simulants, as produced, were shown to not sustain propagating reactions when subjected to a strong ignition source. Additional testing and evaluations are recommended to assess safety concerns associated with postulated ferrocyanide sludge dry-out and exposure to external ignition sources.

  14. Whole Building Energy Simulation

    Broader source: Energy.gov [DOE]

    Whole building energy simulation, also referred to as energy modeling, can and should be incorporated early during project planning to provide energy impact feedback for which design considerations...

  15. Neural Networks 23 (2010) 667668 Contents lists available at ScienceDirect

    E-Print Network [OSTI]

    Fukai, Tomoki

    2010-01-01

    Neural Networks 23 (2010) 667­668 Contents lists available at ScienceDirect Neural Networks journal of large-scale neural network simulations poses the same challenge as experimental data does. This special massively parallel neural recordings and large-scale neural network simulations; (b) Frameworks

  16. Numerical simulations of strong incompressible magnetohydrodynamic turbulence

    SciTech Connect (OSTI)

    Mason, J.; Cattaneo, F.; Perez, J. C.; Boldyrev, S.

    2012-05-15

    Magnetised plasma turbulence pervades the universe and is likely to play an important role in a variety of astrophysical settings. Magnetohydrodynamics (MHD) provides the simplest theoretical framework in which phenomenological models for the turbulent dynamics can be built. Numerical simulations of MHD turbulence are widely used to guide and test the theoretical predictions; however, simulating MHD turbulence and accurately measuring its scaling properties is far from straightforward. Computational power limits the calculations to moderate Reynolds numbers and often simplifying assumptions are made in order that a wider range of scales can be accessed. After describing the theoretical predictions and the numerical approaches that are often employed in studying strong incompressible MHD turbulence, we present the findings of a series of high-resolution direct numerical simulations. We discuss the effects that insufficiencies in the computational approach can have on the solution and its physical interpretation.

  17. Quantum simulation of the Klein paradox

    E-Print Network [OSTI]

    Gerritsma, R; Kirchmair, G; Zähringer, F; Hempel, C; Casanova, J; García-Ripoll, J J; Solano, E; Blatt, R; Roos, C F

    2010-01-01

    In 1929 Oskar Klein obtained a surprising result when investigating the scattering of a relativistic electron from an electrostatic potential step using the Dirac equation. Klein found that the electron can propagate through the step, without damping, and that the probability for this happening increases with the step height---a result commonly known as the Klein paradox. Since direct experimental investigations are lacking, and would be very challenging, the Klein paradox remains a much debated and investigated topic in relativistic quantum mechanics. Driven by the experimental inaccessibility of relativistic quantum systems there has been recent interest in performing quantum simulations. In this paper we report on the quantum simulation of relativistic scattering dynamics and the observation of Klein tunneling, using trapped ions. The combination of precise engineering of all terms in the simulated Hamiltonian and the ability to prepare arbitrary initial states enables the investigation of a wide range of ...

  18. Metropolitan Road Traffic Simulation on FPGAs.

    SciTech Connect (OSTI)

    Tripp J. L. (Justin L.); Mortveit, H. S. (Henning S.); Hansson, A. A. (Anders A.); Gokhale, M. (Maya)

    2005-01-01

    This work demonstrates that road traffic simulation of entire metropolitan areas is possible with reconfigurable supercomputing that combines 64-bit microprocessors and FPGAs in a high bandwidth, low latency interconnect. Previously, traffic simulation on FPGAs was limited to very short road segments or required a very large number of FPGAs. Our data streaming approach overcomes scaling issues associated with direct implementations and still allows for high-level parallelism by dividing the data sets between hardware and software across the reconfigurable supercomputer. Using one FPGA on the Cray XD1 supercomputer, we are able to achieve a 34.4 x speed up over the AMD microprocessor. System integration issues must be optimized to exploit this speedup in the overall simulation.

  19. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-04-30

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation

  20. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation.

  1. Direct cooled power electronics substrate

    DOE Patents [OSTI]

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W. (Kingston, TN) [Kingston, TN; Lowe, Kirk T. (Knoxville, TN) [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  2. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, Michael A. (Los Alamos, NM); Crowell, John M. (Los Alamos, NM)

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  3. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, M.A.; Crowell, J.M.

    1985-04-09

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  4. Sand Simulation Abhinav Golas

    E-Print Network [OSTI]

    Lin, Ming C.

    Sand Simulation Abhinav Golas COMP 768 - Physically Based Simulation Final Project Presentation May (Wikipedia) Size variation from 1m to icebergs Food grains, sand, coal etc. Powders ­ can be suspended 6, 2009 9 0I #12;Understanding the behavior Why can sand sustain shear stress? Friction between

  5. Modeling direct interband tunneling. II. Lower-dimensional structures

    SciTech Connect (OSTI)

    Pan, Andrew; Chui, Chi On

    2014-08-07

    We investigate the applicability of the two-band Hamiltonian and the widely used Kane analytical formula to interband tunneling along unconfined directions in nanostructures. Through comparisons with k·p and tight-binding calculations and quantum transport simulations, we find that the primary correction is the change in effective band gap. For both constant fields and realistic tunnel field-effect transistors, dimensionally consistent band gap scaling of the Kane formula allows analytical and numerical device simulations to approximate non-equilibrium Green's function current characteristics without arbitrary fitting. This allows efficient first-order calibration of semiclassical models for interband tunneling in nanodevices.

  6. NEW DIRECTIONS IN LOCAL HISTORY

    E-Print Network [OSTI]

    Banaji,. Murad

    NEW DIRECTIONS IN LOCAL HISTORY SINCE HOSKINS Edited by Christopher Dyer, Andrew Hopper, Evelyn Lord and Nigel Tringham New Directions in Local History since Hoskins Local history in Britain can of the publication of his Local History in England which was designed to help people researching the history

  7. Computing fractal dimension in supertransient systems directly, fast and reliable

    E-Print Network [OSTI]

    Romulus Breban; Helena E. Nusse

    2006-08-07

    Chaotic transients occur in many experiments including those in fluids, in simulations of the plane Couette flow, and in coupled map lattices and they are a common phenomena in dynamical systems. Superlong chaotic transients are caused by the presence of chaotic saddles whose stable sets have fractal dimensions that are close to phase-space dimension. For many physical systems chaotic saddles have a big impact on laboratory measurements, and it is important to compute the dimension of such stable sets including fractal basin boundaries through a direct method. In this work, we present a new method to compute the dimension of stable sets of chaotic saddles directly, fast, and reliable.

  8. Collimated directional emission from a peanut-shaped microresonator

    E-Print Network [OSTI]

    Shu, Fang-Jie; Sun, Fang-Wen; Xiao, Yun-Feng

    2011-01-01

    Collimated directional emission is essentially required an asymmetric resonant cavity. In this paper, we theoretically investigate a type of peanut-shaped microcavity which can support highly directional emission with the emission divergence as small as 2.5o. The mechanism of the collimated emission is explained with the short-term ray trajectory and the intuitive lens model in detail. Wave simulation also confirms these results. This extremely narrow divergence of the emission holds a great potential in highly collimated lasing from on-chip microcavities.

  9. Mechanism of directional emission from a peanut-shaped microcavity

    SciTech Connect (OSTI)

    Shu Fangjie [Department of Physics, Shangqiu Normal University, Shangqiu 476000 (China); State Key Lab for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China); Zou Changling; Sun Fangwen [Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui 230026 (China); Xiao Yunfeng [State Key Lab for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

    2011-05-15

    Collimated directional emission is essentially required for an asymmetric resonant cavity. In this paper, we theoretically investigate a type of peanut-shaped microcavity which can support highly directional emission with a beam divergence as small as 2.5 deg. The mechanism of the collimated emission of this type of peanut-shaped microcavity is explained with a short-term ray trajectory. Moreover, the explanations are also confirmed by a numerical wave simulation. This extremely narrow divergence of the emission holds great potential in highly collimated lasing from on-chip microcavities.

  10. Carbon Nanotubes Potentialities in Directional Dark Matter Searches

    E-Print Network [OSTI]

    L. M. Capparelli; G. Cavoto; D. Mazzilli; A. D. Polosa

    2014-12-28

    We propose a new solution to the problem of dark matter directional detection based on large parallel arrays of carbon nanotubes. The phenomenon of ion channeling in single wall nanotubes is simulated to calculate the expected number of recoiling carbon ions, due to the hypothetical scattering with dark matter particles, subsequently being driven along their longitudinal extension. As shown by explicit calculation, the relative orientation of the carbon nanotube array with respect to the direction of motion of the Sun has an appreciable effect on the channeling probability of the struck ion and this provides the required detector anisotropic response.

  11. Converting DYNAMO simulations to Powersim Studio simulations

    SciTech Connect (OSTI)

    Walker, La Tonya Nicole; Malczynski, Leonard A.

    2014-02-01

    DYNAMO is a computer program for building and running 'continuous' simulation models. It was developed by the Industrial Dynamics Group at the Massachusetts Institute of Technology for simulating dynamic feedback models of business, economic, and social systems. The history of the system dynamics method since 1957 includes many classic models built in DYANMO. It was not until the late 1980s that software was built to take advantage of the rise of personal computers and graphical user interfaces that DYNAMO was supplanted. There is much learning and insight to be gained from examining the DYANMO models and their accompanying research papers. We believe that it is a worthwhile exercise to convert DYNAMO models to more recent software packages. We have made an attempt to make it easier to turn these models into a more current system dynamics software language, Powersim © Studio produced by Powersim AS2 of Bergen, Norway. This guide shows how to convert DYNAMO syntax into Studio syntax.

  12. Efficient Placement of Directional Antennas

    SciTech Connect (OSTI)

    Pan, Feng; Kasiviswanathan, Shiva

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  13. Galaxies that Shine: radiation-hydrodynamical simulations of disk galaxies

    E-Print Network [OSTI]

    Rosdahl, Joakim; Teyssier, Romain; Agertz, Oscar

    2015-01-01

    Radiation feedback is typically implemented using subgrid recipes in hydrodynamical simulations of galaxies. Very little work has so far been performed using radiation-hydrodynamics (RHD), and there is no consensus on the importance of radiation feedback in galaxy evolution. We present RHD simulations of isolated galaxy disks of different masses with a resolution of 18 pc. Besides accounting for supernova feedback, our simulations are the first galaxy-scale simulations to include RHD treatments of photo-ionisation heating and radiation pressure, from both direct optical/UV radiation and multi-scattered, re-processed infrared (IR) radiation. Photo-heating smooths and thickens the disks and suppresses star formation about as much as the inclusion of ("thermal dump") supernova feedback does. These effects decrease with galaxy mass and are mainly due to the prevention of the formation of dense clouds, as opposed to their destruction. Radiation pressure, whether from direct or IR radiation, has little effect, but ...

  14. Global Feedback Simulator

    SciTech Connect (OSTI)

    2015-10-29

    GFS is a simulation engine that is used for the characterization of Accelerator performance parameters based on the machine layout, configuration and noise sources. It combines extensively tested Feedback models with a longitudinal phase space tracking simulator along with the interaction between the two via beam-based feedback using a computationally efficient simulation engine. The models include beam instrumentation, considerations on loop delays for in both the R and beam-based feedback loops, as well as the ability to inject noise (both correlated and uncorrelated) at different points of the machine including a full characterization of the electron gun performance parameters.

  15. Topological Constraints in Directed Polymer Melts

    E-Print Network [OSTI]

    Serna, Pablo; Nahum, Adam

    2015-01-01

    Polymers in a melt may be subject to topological constraints, as in the example of unlinked polymer rings. How to do statistical mechanics in the presence of such constraints remains a fundamental open problem. We study the effect of topological constraints on a melt of directed polymers using simulations of a simple quasi-2D model. We find that fixing the global topology of the melt to be trivial changes the polymer conformations drastically. Polymers of length $L$ wander in the transverse direction only by a distance of order $(\\ln L)^\\zeta$ with $\\zeta \\simeq 1.5$. This is strongly suppressed in comparison with the Brownian scaling $L^{1/2}$ which holds in the absence of the topological constraint. It is also much less than the prediction $L^{1/4}$ of a mean-field-like `array of obstacles' model: thus we rule out such a model in the present setting. Dynamics are also strongly affected by the constraints, and a tagged monomer in an infinite system performs logarithmically slow subdiffusion. To cast light on...

  16. Droplet structure interactions in direct containment heating

    SciTech Connect (OSTI)

    Baker, L. Jr.; Pilch, M.; Tarbell, W.W.

    1988-01-01

    Direct containment heating (DCH) in light water reactors can occur during severe accidents that involve the meltout of the bottom of the reactor vessel while the vessel is at high pressure. The ejected core debris can heat and pressurize the atmosphere and challenge the integrity of containment. The results of recent large-scale direct containment heating tests in the Surtsey facility at the Sandia National Laboratories have demonstrated the importance of the interactions of core debris with structure. In the DCH-2, -3, and -4 tests, > 50% of the simulated core debris injected into the large vessel was found frozen to the ceiling or sidewalls. This finding led to questions concerning the detailed physics of debris/structure interactions. It was expected that vigorous splashing assisted by gravity would have limited the quantity of frozen debris to much smaller amounts. Accordingly, a search of the technical literature was undertaken in the areas of liquid drop interactions with surfaces and with other liquid drops to provide the bases for modeling. The available information was reviewed for applicability to the DCH process. The results of the search and review led to a correlation for the splashing process and a preliminary explanation of the DCH test results in the form of illustrative models.

  17. SIMULATOR SICKNESS IN A VIRTUAL ENVIRONMENTS DRIVING SIMULATOR

    E-Print Network [OSTI]

    ) (Kennedy, Lane, Berhaum, & Lilienthal, 1993) hasbeen used extensively in studies of simulator sickness stability before and after a simulator experience (Kennedy & Lilienthal, 1995; Kennedy and Stanney, 1996

  18. I. Introduction Simulation Modeling

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    , figure of merit, design of experiments, software testing, software validation, program referability, experimentation technique, simulation methodology, and software engineering. Key Words and Phrases: assessment, program efficiency, code verification, software reliability, software robustness, software certification

  19. Fundamentals of plasma simulation

    SciTech Connect (OSTI)

    Forslund, D.W.

    1985-01-01

    With the increasing size and speed of modern computers, the incredibly complex nonlinear properties of plasmas in the laboratory and in space are being successfully explored in increasing depth. Of particular importance have been numerical simulation techniques involving finite size particles on a discrete mesh. After discussing the importance of this means of understanding a variety of nonlinear plasma phenomena, we describe the basic elements of particle-in-cell simulation and their limitations and advantages. The differencing techniques, stability and accuracy issues, data management and optimization issues are discussed by means of a simple example of a particle-in-cell code. Recent advances in simulation methods allowing large space and time scales to be treated with minimal sacrifice in physics are reviewed. Various examples of nonlinear processes successfully studied by plasma simulation will be given.

  20. Module bay with directed flow

    SciTech Connect (OSTI)

    Torczynski, John R. (Albuquerque, NM)

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  1. 2008 world direct reduction statistics

    SciTech Connect (OSTI)

    NONE

    2009-07-01

    This supplement discusses total direct reduced iron (DRI) production for 2007 and 2008 by process. Total 2008 production by MIDREX(reg sign) direct reduction process plants was over 39.8 million tons. The total of all coal-based processes was 17.6 million tons. Statistics for world DRI production are also given by region for 2007 and 2008 and by year (1970-2009). Capacity utilization for 2008 by process is given. World DRI production by region and by process is given for 1998-2008 and world DRI shipments are given from the 1970s to 2008. A list of world direct reduction plants is included.

  2. Directional fast-neutron detector

    DOE Patents [OSTI]

    Byrd, Roger C. (Albuquerque, NM)

    1994-01-01

    A plurality of omnidirectional radiation detectors are arranged in a close packed symmetrical pattern to form a segmented detector. The output radiation counts from these detectors are arithmetically combined to provide the direction of a source of incident radiation. Directionality is achieved without the use of shielding to provide collimation and background reduction effects. Indeed, output counts from paired detectors are simply subtracted to yield a vector direction toward the radiation source. The counts from all of the detectors can be combined to yield an output signal functionally related to the radiation source strength.

  3. Theory Modeling and Simulation

    SciTech Connect (OSTI)

    Shlachter, Jack

    2012-08-23

    Los Alamos has a long history in theory, modeling and simulation. We focus on multidisciplinary teams that tackle complex problems. Theory, modeling and simulation are tools to solve problems just like an NMR spectrometer, a gas chromatograph or an electron microscope. Problems should be used to define the theoretical tools needed and not the other way around. Best results occur when theory and experiments are working together in a team.

  4. Xyce parallel electronic simulator.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  5. Accelerator simulation using computers

    SciTech Connect (OSTI)

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ``multi-track`` simulation and analysis code can be used for these applications.

  6. Accelerator simulation using computers

    SciTech Connect (OSTI)

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a multi-track'' simulation and analysis code can be used for these applications.

  7. Scalable, efficient epidemiological simulation

    SciTech Connect (OSTI)

    Eubank, S. G. (Stephen G.)

    2001-01-01

    We describe the design and implementation of a system for simulating the spread of disease among individuals in a large urban population over the course of several weeks, In contrast to traditional approaches, we do not assume uniform mixing among large sub-populations or split the population into spatial or demographic subpopulations determined a priori. Instead, we rely on empirical estimates of the social network, or contact patterns, that are produced by TRANSIMS, a large-scale simulation of transportation systems.

  8. A restructurable logic simulator 

    E-Print Network [OSTI]

    Ledford, Gordon Lee

    1985-01-01

    A RESTRUCTURABLE LOGIC SIMULATOR A Thesis GORDON LEE LEDFORD, 111 Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1985 Major Subject: Electrical...) Chanan Singh (Head of Department. ) May 1985 ABSTRACT A Restructurable Logic Simulator (May ]985) Gordon Lee Ledford. III, B. S. , Texas AgrM University Chairman ol' Advisory Committee: Dr. Noel R. Strader, ll Very large scale integration (VLSI...

  9. Advanced Particulate Filter Technologies for Direct Injection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Particulate Filter Technologies for Direct Injection Gasoline Engine Applications Advanced Particulate Filter Technologies for Direct Injection Gasoline Engine Applications...

  10. Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vehicle Technologies Office Merit Review 2014: Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine Development Advanced Gasoline Turbocharged Direct Injection...

  11. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-10-22

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Supersedes DOE O 413.2B.

  12. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-01-08

    To establish the Department's, including the NNSA's, requirements for laboratory-directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Cancels DOE O 413.2. Canceled by DOE O 413.2B.

  13. Directional impedance of geared transmissions

    E-Print Network [OSTI]

    Wang, Albert Duan

    2012-01-01

    The purpose of this research is to develop a design tool for geared actuation systems that experience bidirectional exchange of energy with the environment. Despite the asymmetry of efficiency depending on the direction ...

  14. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-04-19

    The Order establishes DOE requirements and responsibilities for laboratory directed research and development while providing laboratory directors with broad flexibility for program implementation. Cancels DOE O 413.2A. Admin Chg 1, 1-31-11.

  15. Direct Multisearch for Multiobjective Optimization

    E-Print Network [OSTI]

    2010-06-01

    Jun 1, 2010 ... derivatives of the individual functions along directions d in the hypertangent cone to ? at x, f. ? i (x;d) = .... functions (?(·),...,?(·)) or the constant, zero vector of dimension m. ...... Multiobjective GAs, quantative indices, and pattern.

  16. Research Directions in Rewriting Logic ?

    E-Print Network [OSTI]

    Meseguer, José

    introduction to rewriting logic, and to paint in broad strokes the main research directions that, since its and Strategies ? Supported by Office of Naval Research Contracts N00014­95­C­0225 and N00014­96­ C­0114

  17. Results from the DCH-1 (Direct Containment Heating) experiment. [Pressurized melt ejection and direct containment heating

    SciTech Connect (OSTI)

    Tarbell, W.W.; Brockmann, J.E.; Pilch, M.; Ross, J.E.; Oliver, M.S.; Lucero, D.A.; Kerley, T.E.; Arellano, F.E.; Gomez, R.D.

    1987-05-01

    The DCH-1 (Direct Containment Heating) test was the first experiment performed in the Surtsey Direct Heating Test Facility. The test involved 20 kg of molten core debris simulant ejected into a 1:10 scale model of the Zion reactor cavity. The melt was produced by a metallothermic reaction of iron oxide and aluminum powders to yield molten iron and alumina. The cavity model was placed so that the emerging debris propagated directly upwards along the vertical centerline of the chamber. Results from the experiment showed that the molten material was ejected from the caviity as a cloud of particles and aerosol. The dispersed debris caused a rapid pressurization of the 103-m/sup 3/ chamber atmosphere. Peak pressure from the six transducers ranged from 0.09 to 0.13 MPa (13.4 to 19.4 psig) above the initial value in the chamber. Posttest debris collection yielded 11.6 kg of material outside the cavity, of which approximately 1.6 kg was attributed to the uptake of oxygen by the iron particles. Mechanical sieving of the recovered debris showed a lognormal size distribution with a mass mean size of 0.55 mm. Aerosol measurements indicated a subsantial portion (2 to 16%) of the ejected mass was in the size range less than 10 m aerodynamic equivalent diameter.

  18. Experiments + Simulations = Better Nuclear Power Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Experiments + Simulations Better Nuclear Power Research Experiments Simulations Better Nuclear Power Research Atomic Level Simulations Enhance Characterization of Radiation...

  19. The Integrated Plasma Simulator: A Flexible Python Framework for Coupled Multiphysics Simulation

    SciTech Connect (OSTI)

    Foley, Samantha S [ORNL; Elwasif, Wael R [ORNL; Bernholdt, David E [ORNL

    2011-11-01

    High-fidelity coupled multiphysics simulations are an increasingly important aspect of computational science. In many domains, however, there has been very limited experience with simulations of this sort, therefore research in coupled multiphysics often requires computational frameworks with significant flexibility to respond to the changing directions of the physics and mathematics. This paper presents the Integrated Plasma Simulator (IPS), a framework designed for loosely coupled simulations of fusion plasmas. The IPS provides users with a simple component architecture into which a wide range of existing plasma physics codes can be inserted as components. Simulations can take advantage of multiple levels of parallelism supported in the IPS, and can be controlled by a high-level ``driver'' component, or by other coordination mechanisms, such as an asynchronous event service. We describe the requirements and design of the framework, and how they were implemented in the Python language. We also illustrate the flexibility of the framework by providing examples of different types of simulations that utilize various features of the IPS.

  20. Efficient simulation of relativistic fermions via vertex models

    SciTech Connect (OSTI)

    Wenger, Urs

    2009-10-01

    We have developed an efficient simulation algorithm for strongly interacting relativistic fermions in two-dimensional field theories based on a formulation as a loop gas. It essentially eliminates critical slowing down by sampling two-point correlation functions and allows simulations directly in the massless limit at the critical point. It generates loop configurations with fluctuating topological boundary conditions enabling one to simulate fermions with arbitrary periodic or antiperiodic boundary conditions. As illustrative examples, the algorithm is applied to the Gross-Neveu model and to the Schwinger model in the strong coupling limit.

  1. Directions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferencesPlatinum FuelEnergy

  2. Dislocation dynamics simulations of plasticity at small scales

    SciTech Connect (OSTI)

    Zhou, Caizhi

    2010-12-15

    As metallic structures and devices are being created on a dimension comparable to the length scales of the underlying dislocation microstructures, the mechanical properties of them change drastically. Since such small structures are increasingly common in modern technologies, there is an emergent need to understand the critical roles of elasticity, plasticity, and fracture in small structures. Dislocation dynamics (DD) simulations, in which the dislocations are the simulated entities, offer a way to extend length scales beyond those of atomistic simulations and the results from DD simulations can be directly compared with the micromechanical tests. The primary objective of this research is to use 3-D DD simulations to study the plastic deformation of nano- and micro-scale materials and understand the correlation between dislocation motion, interactions and the mechanical response. Specifically, to identify what critical events (i.e., dislocation multiplication, cross-slip, storage, nucleation, junction and dipole formation, pinning etc.) determine the deformation response and how these change from bulk behavior as the system decreases in size and correlate and improve our current knowledge of bulk plasticity with the knowledge gained from the direct observations of small-scale plasticity. Our simulation results on single crystal micropillars and polycrystalline thin films can march the experiment results well and capture the essential features in small-scale plasticity. Furthermore, several simple and accurate models have been developed following our simulation results and can reasonably predict the plastic behavior of small scale materials.

  3. Directives Review Board - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections Management'sDirectives

  4. Snowmass Energy Frontier Simulations

    E-Print Network [OSTI]

    Jacob Anderson; Aram Avetisyan; Raymond Brock; Sergei Chekanov; Timothy Cohen; Nitish Dhingra; James Dolen; James Hirschauer; Kiel Howe; Ashutosh Kotwal; Tom LeCompte; Sudhir Malik; Patricia Mcbride; Kalanand Mishra; Meenakshi Narain; Jim Olsen; Sanjay Padhi; Michael E. Peskin; John Stupak III; Jay G. Wacker

    2013-09-01

    This document describes the simulation framework used in the Snowmass Energy Frontier studies for future Hadron Colliders. An overview of event generation with {\\sc Madgraph}5 along with parton shower and hadronization with {\\sc Pythia}6 is followed by a detailed description of pile-up and detector simulation with {\\sc Delphes}3. Details of event generation are included in a companion paper cited within this paper. The input parametrization is chosen to reflect the best object performance expected from the future ATLAS and CMS experiments; this is referred to as the "Combined Snowmass Detector". We perform simulations of $pp$ interactions at center-of-mass energies $\\sqrt{s}=$ 14, 33, and 100 TeV with 0, 50, and 140 additional $pp$ pile-up interactions. The object performance with multi-TeV $pp$ collisions are studied for the first time using large pile-up interactions.

  5. Simulating neural systems with Xyce.

    SciTech Connect (OSTI)

    Schiek, Richard Louis; Thornquist, Heidi K.; Mei, Ting; Warrender, Christina E.; Aimone, James Bradley; Teeter, Corinne; Duda, Alex M.

    2012-12-01

    Sandia's parallel circuit simulator, Xyce, can address large scale neuron simulations in a new way extending the range within which one can perform high-fidelity, multi-compartment neuron simulations. This report documents the implementation of neuron devices in Xyce, their use in simulation and analysis of neuron systems.

  6. Simulating Merging Galaxies: The Infrared View

    E-Print Network [OSTI]

    Sukanya Chakrabarti

    2006-10-29

    We calculate multi-wavelength spectral energy distributions (SEDs) (spanning optical to millimeter wavelengths) from simulations of major galaxy mergers using a three-dimensional radiative transfer code, which treats the absorption and scattering of radiation as well as the reemission from dust grains self-consistently. These calculations allow us to deduce correlations from the X-rays to millimeter wavelengths. We confirm observed correlations for Spitzer Space Telescope's IRAC bands, as well as correlations observed in the IRAS era. We also make predictions that should be testable by future instruments. The power of the dynamical approach afforded by calculating fluxes from the merger simulations is that we can directly correlate observed clustering in the data as seen in IRAC color-color plots with the relative amount of time the system spends in a region of color-color space. We also present photo albums spanning the lifetime of SMGs, from its infancy in the pre-merger phase to its final stage as an elliptical galaxy, as seen in various bands. Finally, we compare the SEDs from the simulations to recent observations of SMGs. Our calculations, which match observed correlations both for local ULIRGs and higher redshift systems, suggest that simulations of major mergers with black hole feedback provide an excellent framework within which to understand the emission from local ULIRGs, and their high redshift cousins, the submillimeter galaxies.

  7. Laboratory Facility for Simulating Solar Wind Sails

    SciTech Connect (OSTI)

    Funaki, Ikkoh [Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, 229-8510 (Japan); JST/CREST, Kawaguchi, Saitama, 332-0012 (Japan); Ueno, Kazuma; Oshio, Yuya [Graduate University for Advanced Studies, Sagamihara, Kanagawa, 229-8510 (Japan); Ayabe, Tomohiro; Horisawa, Hideyuki [Tokai University, Hiratsuka, Kanagawa, 259-1292 (Japan); Yamakawa, Hiroshi [Kyoto University, Uji, Kyoto, 611-0011 (Japan); JST/CREST, Kawaguchi, Saitama, 332-0012 (Japan)

    2008-12-31

    Magnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 10{sup 19} m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail.

  8. Fast Generators of Direct Photons

    E-Print Network [OSTI]

    S. M. Kiselev

    2008-11-17

    Three fast generators of direct photons in the central rapidity region of high-energy heavy-ion collisions have been presented The generator of prompt photons is based on a tabulation of $p+p(\\bar p)$ data and binary scaling. Two generators of thermal direct photons, for hot hadron gas (HHG) and quark-gluon plasma (QGP) scenarios, assume the 1+1 Bjorken hydrodynamics. SPS and RHIC data can be fitted better by scenario with QGP. Predictions for the LHC energy have been made. The generators have been realized as macros for the ROOT analysis package.

  9. Directions to Wilson Hall, Fermilab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirections &Directions Both

  10. Kinetics modeling and 3-dimensional simulation of surface roughness during plasma etching

    E-Print Network [OSTI]

    Guo, Wei, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    The control of feature profiles in directional plasma etching processes is crucial as critical dimension, line-edge roughening, and other artifacts affect device performance and process yields. A profile simulator is ...

  11. Simulation of Earthquake Liquefaction Response on Parallel Computers , K. H. Law3

    E-Print Network [OSTI]

    Stanford University

    sparse direct solver. Simulation results of grid models and a centrifuge test model using ParCYCLIC, the calibrated serial code for modeling of earthquake geotechnical phenomena is combined with advanced

  12. Use of an Engine Cycle Simulation to Study a Biodiesel Fueled Engine 

    E-Print Network [OSTI]

    Zheng, Junnian

    2010-01-14

    Based on the GT-Power software, an engine cycle simulation for a biodiesel fueled direct injection compression ignition engine was developed and used to study its performance and emission characteristics. The major objectives were to establish...

  13. A Conformal Mapping Grid Generation Method for Modeling High-Fidelity Aeroelastic Simulations 

    E-Print Network [OSTI]

    Worley, Gregory

    2010-07-14

    This work presents a method for building a three-dimensional mesh from two- dimensional topologically identical layers, for use in aeroelastic simulations. The method allows modeling of large deformations of the wing in both the span direction...

  14. FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTED FRAME TRANSFORMATION

    E-Print Network [OSTI]

    Fawley, William

    2010-01-01

    FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTEDrest frame), the red-shifted FEL radiation and blue-shiftedper- mit direct study of FEL problems for which the eikonal

  15. QPE: Using assumption-based truth maintenance for qualitative simulation

    E-Print Network [OSTI]

    Forbus, Kenneth D.

    writin g such programs. This paper identifies several abstractions for organizing ATMS-based problem a mechanism for making closed-world assumptions . We sketch the design of the Qualitative Process Engine, QPE simulation as a module in a larger task . All of these research directions require substantially more

  16. Shell to shell energy transfer in magnetohydrodynamic dynamo simulations

    E-Print Network [OSTI]

    Pouquet, Annick

    Shell to shell energy transfer in magnetohydrodynamic dynamo simulations Pablo Mininni, Alexandros 80307 (Dated: May 5, 2005) We study the transfer of energy between different scales for forced three, and which scales of the magnetic field receive energy directly from the velocity field and which scales

  17. Exit Counseling Guide for Direct Loan Borrowers You borrowed Direct Subsidized Loans and/or

    E-Print Network [OSTI]

    Minnesota, University of

    Exit Counseling Guide for Direct Loan Borrowers You borrowed Direct Subsidized Loans and/or Direct of Education. The word "loan" refers to one or more Direct Subsidized Loans or Direct Unsubsidized Loans Subsidized Loans) · Federal Direct Unsubsidized Stafford/Ford Loans (Direct Unsubsidized Loans) · Federal

  18. TROPICAL STORMS SUPER SIMULATIONS

    E-Print Network [OSTI]

    Fukai, Tomoki

    physical sciences 15 A new flavor of superconductor Computer simulations show how fundamental particles behave like electrons in a superconductor 16 Higgs versus the Big Bang The Higgs boson could help explain The magnetic interactions in beryllium-11 could explain its unusual shape 19 A solitary superconductor emerges

  19. Simulating Inhomogeneous Reionization

    E-Print Network [OSTI]

    Michael L. Norman; Paschalis Paschos; Tom Abel

    1998-07-28

    We describe an approach for incorporating radiative transfer into 3D hydrodynamic cosmological simulations. The method, while approximate, allows for a self-consistent treatment of self-shielding and shadowing, diffuse and point sources of radiation, and frequency dependent transfer. Applications include photodissociation, photoheating, and photoionization of the IGM.

  20. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch Mary Jean Brown, Sc.D., R that affects practically all systems in the human body (National Research Council, 1993). In children children in the United States decreased from 8.6 percent in 1988­1991 to 1.6 percent in 1999­2002, an 81

  1. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-04-19

    The order establishes DOE requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Cancels DOE O 413.3A. Admin Chg 1, dated 1-31-11, cancels DOE O 413.2B. Certified 7-14-2011.

  2. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch CAPTMarkD.Miller U.S.P.H.S.,R.S.,M.P.H. Emergency Preparedness and Response Training for Environmental Health Practitioners Editor's note: NEHA strives to provide up- to-date and relevant information on en- vironmental health and to build partner

  3. Direct Hamiltonization for Nambu Systems

    E-Print Network [OSTI]

    Maria Lewtchuk Espindola

    2008-10-13

    The direct hamiltonization procedure applied to Nambu mechanical systems proves that the Nambu mechanics is an usual mechanics described by only one Hamiltonian. Thus a particular case of Hamiltonian mechanics. It is also proved that any mechanical system described by the equation d{\\bf r}/dt={\\bf A(r)} is a Nambu system.

  4. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch Editor's note: NEHA strives to provide up-to-date and relevant information on environmental health and to build part nerships in the profession. In pursuit of these goals, we feature a column from the Environmental Health Services Branch (EHSB) of the Centers

  5. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    of prec Direct from CDC Environmental Health Services Branch Martin A. Kalis, M and relevant information on environmen tal health and to build partnerships in the pro fession. In pursuit of these goals, we feature a column from the Environmental Health Ser vices Branch (EHSB) of the Centers for Dis

  6. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch JeffreyS.Neistadt,M.S.,R.S. TimothyJ.Murphy,Ph.D.,R.E.H.S. Are We Really Saving Resources with Current Hiring Practices at Local Health Departments? Editor's note: NEHA strives to provide up-to-date and relevant information on environmental health and to build

  7. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch HilaryHeishman,M.P.H. CAPTAndrew-date and relevant information on envi ronmental health and to build partnerships in the profession. In pursuit of these goals, we feature a column from the Environmen tal Health Services Branch (EHSB) of the Centers

  8. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch CAPT John P. Sarisky, R.S., M.P.H. The Environmental Public Health Performance Standards: Strengthening the Nation's Environmental Public Health Infrastructure and Improving Environmental Health Practice Editor's note: NEHA strives to provide up

  9. Direct from CDC Environmental Health

    E-Print Network [OSTI]

    Direct from CDC Environmental Health Services Branch KateWright,M.P.H.,Ed.D. Environmental Public Health Leadership Development Editor's note: NEHA strives to provide up-to-date and relevant information on environmental health and to build part nerships in the profession. In pursuit of these goals, we feature

  10. Enterprise Risk Management (ERM) Framework for Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2012-09-30

    Explains the new ERM framework for developing, revising, and reviewing directives. This memo directs the Office of Management to institutionalize ERM into the directives process no later than September 30, 2012.

  11. DIRECT PHOTONS FROM Y(3100) DECAY

    E-Print Network [OSTI]

    Ronan, M.T.

    2010-01-01

    to search for direct photons from 0(3100) decay. V* havedecay, but a sianal of high energy direct photons remains.this excess of direct photons wi*h OCD predictions and

  12. Future Directions in Spatial Demography, Position Papers

    E-Print Network [OSTI]

    Center for Spatial Studies (UCSB), Population Research Institute (Pennsylvania State University)

    2011-01-01

    2011 Specialist Meeting—Future Directions in Spatial3–13. 2011 Specialist Meeting—Future Directions in SpatialInc. 2011 Specialist Meeting—Future Directions in Spatial

  13. Comparing Membrane Simulations to Scattering Experiments: Introducing the SIMtoEXP Software

    E-Print Network [OSTI]

    Nagle, John F.

    of biomembrane simulations with experimental X-ray and neutron scattering data. It has the following features: (1 the electron density e(z) and neutron scattering length density m(z) profiles along the z direction (i.e., nor simulation Á X-ray scattering Á Neutron scattering Á Computer software Introduction It is well recognized

  14. Numerical simulation of vortical flows in the near field of jets from notched circular nozzles

    E-Print Network [OSTI]

    Liu, Feng

    Numerical simulation of vortical flows in the near field of jets from notched circular nozzles Keywords: Jet Vortex Computational fluid dynamics Direct numerical simulation Non-circular nozzles a b s t r a c t The vortex dominated flows in the near field of jets from notched circular nozzles

  15. Upstream entrainment in numerical simulations of spatially evolving Pradeep C. Babu and Krishnan Mahesha)

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Upstream entrainment in numerical simulations of spatially evolving round jets Pradeep C. Babu) Direct numerical simulation is used to study the effect of entrainment near the inflow nozzle on spatially evolving round jets. Inflow entrainment is obtained by providing a buffer region upstream

  16. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Direct Kinetic Measurements of a Criegee Intermediate Direct Kinetic Measurements of a Criegee Intermediate Print Wednesday, 25 January 2012 00:00 In the earth's troposphere, which...

  17. Directional Drilling Systems | Open Energy Information

    Open Energy Info (EERE)

    Directional Drilling Systems Jump to: navigation, search Geothermal ARRA Funded Projects for Directional Drilling Systems Loading map... "format":"googlemaps3","type":"ROADMAP","t...

  18. Investigation of Direct Injection Vehicle Particulate Matter...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Direct Injection Vehicle Particulate Matter Emissions Investigation of Direct Injection Vehicle Particulate Matter Emissions This study focuses primarily on particulate matter mass...

  19. PEBBLES Mechanics Simulation Speedup

    SciTech Connect (OSTI)

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2010-05-01

    Pebble bed reactors contain large numbers of spherical fuel elements arranged randomly. Determining the motion and location of these fuel elements is required for calculating certain parameters of pebble bed reactor operation. These simulations involve hundreds of thousands of pebbles and involve determining the entire core motion as pebbles are recirculated. Single processor algorithms for this are insufficient since they would take decades to centuries of wall-clock time. This paper describes the process of parallelizing and speeding up the PEBBLES pebble mechanics simulation code. Both shared memory programming with the Open Multi-Processing API and distributed memory programming with the Message Passing Interface API are used in simultaneously in this process. A new shared memory lock-less linear time collision detection algorithm is described. This method allows faster detection of pebbles in contact than generic methods. These combine to make full recirculations on AVR sized reactors possible in months of wall clock time.

  20. BIOMECHANICAL MODELING AND SIMULATION WITHIN A MEDICAL SIMULATOR FRAMEWORK

    E-Print Network [OSTI]

    Wolf, Christian

    BIOMECHANICAL MODELING AND SIMULATION WITHIN A MEDICAL SIMULATOR FRAMEWORK -- 18 months post the LIRIS Lab. (http://liris.cnrs.fr/~saara) is involved in the elaboration of an optimal biomechanical in the development of modules for bio-mechanical modeling and simulation, and their integrated within a framework (i

  1. Statistical simulation procedures 

    E-Print Network [OSTI]

    Tremelling, Robert Norman

    1970-01-01

    that theoretical procedures are im- practical. Thus, with the advent of the electronic computer, numeri ca'I or simul ation procedures for ap- proximating this distribution function have been de- veloped. For the extension of the Stratified Monte Carlo (S. M... distribution functions ano their parameters. With the rising importance of statistics, and the advent of the computer, Honte Carlo methods are just now being investigated. Although definitions of Honte Carlo samplino may differ, it is usually associated...

  2. OM300 Direction Drilling Module

    SciTech Connect (OSTI)

    MacGugan, Doug

    2013-08-22

    OM300 – Geothermal Direction Drilling Navigation Tool: Design and produce a prototype directional drilling navigation tool capable of high temperature operation in geothermal drilling Accuracies of 0.1° Inclination and Tool Face, 0.5° Azimuth Environmental Ruggedness typical of existing oil/gas drilling Multiple Selectable Sensor Ranges High accuracy for navigation, low bandwidth High G-range & bandwidth for Stick-Slip and Chirp detection Selectable serial data communications Reduce cost of drilling in high temperature Geothermal reservoirs Innovative aspects of project Honeywell MEMS* Vibrating Beam Accelerometers (VBA) APS Flux-gate Magnetometers Honeywell Silicon-On-Insulator (SOI) High-temperature electronics Rugged High-temperature capable package and assembly process

  3. Rayleigh-Taylor Growth Stabilization in Direct-Drive Plastic Targets at Laser Intensities of 1 1015

    E-Print Network [OSTI]

    Rochester, New York 14623-1299, USA J. A. Frenje and R. D. Petrasso Plasma Science and Fusion Center,5] and direct [6­9] drive, mostly in planar geometry. Both classical and ablative RT instability linear growth-front heating when plasma corona temperatures exceed 3 keV. Direct-drive experiments and simulations have shown

  4. Wellbore inertial directional surveying system

    DOE Patents [OSTI]

    Andreas, R.D.; Heck, G.M.; Kohler, S.M.; Watts, A.C.

    1982-09-08

    A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single offshore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on an electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block about the gimbal axis. Angular rates of the sensor block about axes which are perpendicular to te gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and angular rate information. Kalman estimation techniques are used to compensate for system errors. 25 figures.

  5. Wellbore inertial directional surveying system

    DOE Patents [OSTI]

    Andreas, Ronald D. (Albuquerque, NM); Heck, G. Michael (Albuquerque, NM); Kohler, Stewart M. (Albuquerque, NM); Watts, Alfred C. (Albuquerque, NM)

    1991-01-01

    A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single off-shore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on the electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block aboutthe gimbal axis. Angular rates of the sensor block about axes which are perpendicular to the gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and anular rate information. Kalman estimation techniques are used to compensate for system errors.

  6. CFD Simulation of Riser VIV 

    E-Print Network [OSTI]

    Huang, Zhiming

    2012-07-16

    The dissertation presents a CFD approach for 3D simulation of long risers. Long riser VIV simulation is at the frontier of the CFD research area due to its high demand on computational resources and techniques. It also has ...

  7. Simulations of nanoscale spatial disorder

    E-Print Network [OSTI]

    Howe, Ethan (Ethan Gabriel Grief)

    2006-01-01

    In this thesis, we detail the design, implementation, and testing of two simulations of nanometer scale disorder phenomena important for electronic device fabrication. We created a kinetic simulator for the surface assembly ...

  8. Design of mechanical arterial simulator

    E-Print Network [OSTI]

    Chai, Lauren (Lauren Amy)

    2012-01-01

    A force controlled ultrasound probe is being explored as a new method of measuring blood pressure. An arterial simulator was designed and built for experiments. For this simulator, the vessels and bulk material were designed ...

  9. FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects

    SciTech Connect (OSTI)

    Koch, D

    2011-09-21

    The global and annual mean aerosol direct and indirect effects, relative to 1850 conditions, estimated from CESM simulations are 0.02 W m-2 and -0.39 W m-2, respectively, for emissions in year 2100 under the IPCC RCP8.5 scenario. The indirect effect is much smaller than that for 2000 emissions because of much smaller SO2 emissions in 2100; the direct effects are small due to compensation between warming by black carbon and cooling by sulfate.

  10. Crossed-beam energy transfer in direct-drive implosions

    SciTech Connect (OSTI)

    Seka, W; Edgell, D H; Michel, D T; Froula, D H; Goncharov, V N; Craxton, R S; Divol, L; Epstein, R; Follett, R; Kelly, J H; Kosc, T Z; Maximov, A V; McCrory, R L; Meyerhofer, D D; Michel, P; Myatt, J F; Sangster, T C; Shvydky, A; Skupsky, S

    2012-05-22

    Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of the scattered (non-absorbed) light levels and measured ones that indicate the presence of a mechanism that reduces laser coupling efficiency by 10%-20%. This appears to be due to crossed-beam energy transfer (CBET) that involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters energy from the central portion of the incoming light beam to outgoing light, reducing the laser absorption and hydrodynamic efficiency of implosions. One-dimensional hydrodynamic simulations including CBET show good agreement with all observables in implosion experiments on OMEGA. Three strategies to mitigate CBET and improve laser coupling are considered: the use of narrow beams, multicolor lasers, and higher-Z ablators. Experiments on OMEGA using narrow beams have demonstrated improvements in implosion performance.

  11. Directives Up for Review FY 2016 - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileepDirectionsRequirements

  12. Simulation of Sextet Diquark Production

    E-Print Network [OSTI]

    Peter Richardson; David Winn

    2011-11-22

    We present a method for simulating the production and decay of particles in the sextet representation of $SU(3)_C$ including the simulation of QCD radiation. First results from the Monte Carlo simulation of sextet diquark production at the LHC including both resonant and pair production are presented. We include limits on resonant diquark production from recent ATLAS results and perform the first simulation studies of the less model dependent pair production mechanism.

  13. Computer Simulations of Protein Folding

    E-Print Network [OSTI]

    Sorin, Eric J.

    CHAPTER 8 Computer Simulations of Protein Folding VIJAY S. PANDE , ERIC J. SORIN , CHRISTOPHER D, CA 94305, USA 8.1 Introduction: Goals and Challenges of Simulating Protein Folding Computer as well as recent applications of this methodology. 8.1.1 Simulating Protein Folding Proteins play

  14. Bio-threat microparticle simulants

    DOE Patents [OSTI]

    Farquar, George Roy; Leif, Roald

    2014-09-16

    A bio-threat simulant that includes a carrier and DNA encapsulated in the carrier. Also a method of making a simulant including the steps of providing a carrier and encapsulating DNA in the carrier to produce the bio-threat simulant.

  15. Simulations of an offshore wind farm using large eddy simulation and a torque-controlled actuator disc model

    E-Print Network [OSTI]

    Creech, Angus; Maguire, A Eoghan

    2014-01-01

    We present here a computational fluid dynamics (CFD) simulation of Lillgrund offshore wind farm, which is located in the {\\O}resund Strait between Sweden and Denmark. The simulation combines a dynamic representation of wind turbines embedded within a Large-Eddy Simulation CFD solver, and uses hr-adaptive meshing to increase or decrease mesh resolution where required. This allows the resolution of both large scale flow structures around the wind farm, and local flow conditions at individual turbines; consequently, the response of each turbine to local conditions can be modelled, as well as the resulting evolution of the turbine wakes. This paper provides a detailed description of the turbine model which simulates interactions between the wind, turbine rotors, and turbine generators by calculating the forces on the rotor, the body forces on the air, and instantaneous power output. This model was used to investigate a selection of key wind speeds and directions, investigating cases where a row of turbines would ...

  16. The Environment and Directed Technical Change

    E-Print Network [OSTI]

    Acemoglu, Daron

    This paper introduces endogenous and directed technical change in a growth model with environmental

  17. Direct handling of sharp interfacial energy for microstructural evolution

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hernández–Rivera, Efraín; Tikare, Veena; Noirot, Laurence; Wang, Lumin

    2014-08-24

    In this study, we introduce a simplification to the previously demonstrated hybrid Potts–phase field (hPPF), which relates interfacial energies to microstructural sharp interfaces. The model defines interfacial energy by a Potts-like discrete interface approach of counting unlike neighbors, which we use to compute local curvature. The model is compared to the hPPF by studying interfacial characteristics and grain growth behavior. The two models give virtually identical results, while the new model allows the simulator more direct control of interfacial energy.

  18. 1997 Laboratory directed research and development. Annual report

    SciTech Connect (OSTI)

    Meyers, C.E.; Harvey, C.L.; Chavez, D.L.; Whiddon, C.P.

    1997-12-31

    This report summarizes progress from the Laboratory Directed Research and Development (LDRD) program during fiscal year 1997. In addition to a programmatic and financial overview, the report includes progress reports from 218 individual R&D projects in eleven categories. Theses reports are grouped into the following areas: materials science and technology; computer sciences; electronics and photonics; phenomenological modeling and engineering simulation; manufacturing science and technology; life-cycle systems engineering; information systems; precision sensing and analysis; environmental sciences; risk and reliability; national grand challenges; focused technologies; and reserve.

  19. Laboratory Directed Research and Development FY 2000 Annual Progress Report

    SciTech Connect (OSTI)

    Los Alamos National Laboratory

    2001-05-01

    This is the FY00 Annual Progress report for the Laboratory Directed Research and Development (LDRD) Program at Los Alamos National Laboratory. It gives an overview of the LDRD Program, summarizes progress on each project conducted during FY00, characterizes the projects according to their relevance to major funding sources, and provides an index to principal investigators. Project summaries are grouped by LDRD component: Directed Research and Exploratory Research. Within each component, they are further grouped into the ten technical categories: (1) atomic, molecular, optical, and plasma physics, fluids, and beams, (2) bioscience, (3) chemistry, (4) computer science and software engineering, (5) engineering science, (6) geoscience, space science, and astrophysics, (7) instrumentation and diagnostics, (8) materials science, (9) mathematics, simulation, and modeling, and (10) nuclear and particle physics.

  20. Mesh infrastructure for coupled multiprocess geophysical simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Garimella, Rao V.; Perkins, William A.; Buksas, Mike W.; Berndt, Markus; Lipnikov, Konstantin; Coon, Ethan; Moulton, John D.; Painter, Scott L.

    2014-01-01

    We have developed a sophisticated mesh infrastructure capability to support large scale multiphysics simulations such as subsurface flow and reactive contaminant transport at storage sites as well as the analysis of the effects of a warming climate on the terrestrial arctic. These simulations involve a wide range of coupled processes including overland flow, subsurface flow, freezing and thawing of ice rich soil, accumulation, redistribution and melting of snow, biogeochemical processes involving plant matter and finally, microtopography evolution due to melting and degradation of ice wedges below the surface. In addition to supporting the usual topological and geometric queries about themore »mesh, the mesh infrastructure adds capabilities such as identifying columnar structures in the mesh, enabling deforming of the mesh subject to constraints and enabling the simultaneous use of meshes of different dimensionality for subsurface and surface processes. The generic mesh interface is capable of using three different open source mesh frameworks (MSTK, MOAB and STKmesh) under the hood allowing the developers to directly compare them and choose one that is best suited for the application's needs. We demonstrate the results of some simulations using these capabilities as well as present a comparison of the performance of the different mesh frameworks.« less

  1. Evolution of analyzing reservoir simulation data

    SciTech Connect (OSTI)

    Phelps, R.E.; Huang, A.Y.

    1994-12-31

    Numerical Reservoir Simulation is routinely used by the petroleum producing companies world-wide as an engineering tool to efficiently manage their hydrocarbon reservoirs. The task of building models with a large number of grid-blocks is not easy, and to analyze the voluminous results produced by such models is even more difficult. This paper discusses the historical evolution of techniques used to analyze reservoir simulation data over the past decade. It outlines how the advancement of workstation technology and the introduction of X-Window System opened up an entirely new way of utilizing mainframe computing power and workstation graphical display capabilities, simultaneously. The paper also discusses Saudi Aramco`s experience in the development of sophisticated reservoir simulation post-processing packages. The need for direct communication between the programmer and end-users to facilitate a user-friendly package is emphasized. A practical example illustrating the benefit of these post-processing packages in the construction and history matching of a large model with approximately 52,000 cells is presented. Savings in manpower and computer resources using current technology are estimated.

  2. Evolution of analyzing reservoir simulation data

    SciTech Connect (OSTI)

    Phelps, R.E.; Huang, A.Y.

    1995-12-01

    Petroleum-producing companies world-wide routinely use numerical reservoir simulation as an engineering tool to manage their hydrocarbon reservoirs efficiently. The task of building models with a large number of gridblocks is not easy, and analyzing the voluminous results produced by such models is even more difficult. This paper discusses the historical evolution of techniques used to analyze reservoir simulation data over the past decade. It outlines how the advancement of workstation technology and the introduction of an X-Window system opened up an entirely new way of using mainframe computing power and workstation graphical display capabilities simultaneously. The paper also discusses Saudi Aramco`s experience in the development of sophisticated reservoir simulation postprocessing packages. The authors emphasize the need for direct communication between the programmer and end users to facilitate a user-friendly package. They present a practical example illustrating the benefit of these postprocessing packages in the construction and history matching of a large model with approximately 52,000 cells. They estimate savings in manpower and computer resources using current technology.

  3. Mesh infrastructure for coupled multiprocess geophysical simulations

    SciTech Connect (OSTI)

    Garimella, Rao V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perkins, William A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buksas, Mike W. [Stellar Science Ltd. Co., Albuquerque, NM (United States); Berndt, Markus [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lipnikov, Konstantin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Coon, Ethan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moulton, John D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Painter, Scott L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-01

    We have developed a sophisticated mesh infrastructure capability to support large scale multiphysics simulations such as subsurface flow and reactive contaminant transport at storage sites as well as the analysis of the effects of a warming climate on the terrestrial arctic. These simulations involve a wide range of coupled processes including overland flow, subsurface flow, freezing and thawing of ice rich soil, accumulation, redistribution and melting of snow, biogeochemical processes involving plant matter and finally, microtopography evolution due to melting and degradation of ice wedges below the surface. In addition to supporting the usual topological and geometric queries about the mesh, the mesh infrastructure adds capabilities such as identifying columnar structures in the mesh, enabling deforming of the mesh subject to constraints and enabling the simultaneous use of meshes of different dimensionality for subsurface and surface processes. The generic mesh interface is capable of using three different open source mesh frameworks (MSTK, MOAB and STKmesh) under the hood allowing the developers to directly compare them and choose one that is best suited for the application's needs. We demonstrate the results of some simulations using these capabilities as well as present a comparison of the performance of the different mesh frameworks.

  4. Software Framework for Advanced Power Plant Simulations

    SciTech Connect (OSTI)

    John Widmann; Sorin Munteanu; Aseem Jain; Pankaj Gupta; Mark Moales; Erik Ferguson; Lewis Collins; David Sloan; Woodrow Fiveland; Yi-dong Lang; Larry Biegler; Michael Locke; Simon Lingard; Jay Yun

    2010-08-01

    This report summarizes the work accomplished during the Phase II development effort of the Advanced Process Engineering Co-Simulator (APECS). The objective of the project is to develop the tools to efficiently combine high-fidelity computational fluid dynamics (CFD) models with process modeling software. During the course of the project, a robust integration controller was developed that can be used in any CAPE-OPEN compliant process modeling environment. The controller mediates the exchange of information between the process modeling software and the CFD software. Several approaches to reducing the time disparity between CFD simulations and process modeling have been investigated and implemented. These include enabling the CFD models to be run on a remote cluster and enabling multiple CFD models to be run simultaneously. Furthermore, computationally fast reduced-order models (ROMs) have been developed that can be 'trained' using the results from CFD simulations and then used directly within flowsheets. Unit operation models (both CFD and ROMs) can be uploaded to a model database and shared between multiple users.

  5. House Simulation Protocols Report | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    House Simulation Protocols Report House Simulation Protocols Report Report cover Building America's House Simulation Protocols report is designed to assist researchers in tracking...

  6. Direct measure of quantum correlation

    SciTech Connect (OSTI)

    Yu, Chang-shui [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Zhao, Haiqing [School of Science, Dalian Jiaotong University, Dalian 116028 (China)

    2011-12-15

    The quantumness of the correlation known as quantum correlation is usually measured by quantum discord. So far various quantum discords can be roughly understood as indirect measure by some special discrepancy of two quantities. We present a direct measure of quantum correlation by revealing the difference between the structures of classically and quantum correlated states. Our measure explicitly includes the contributions of the inseparability and local nonorthogonality of the eigenvectors of a density matrix. Besides its relatively easy computability, our measure can provide a unified understanding of quantum correlation of all the present versions.

  7. Direct application of geothermal energy

    SciTech Connect (OSTI)

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  8. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet Hanford AdvisoryEnergy LessonsDIRECTIVES,DOE

  9. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet Hanford AdvisoryEnergy LessonsDIRECTIVES,DOEJim McDonald

  10. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet Hanford AdvisoryEnergy LessonsDIRECTIVES,DOEJim

  11. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet Hanford AdvisoryEnergy LessonsDIRECTIVES,DOEJimPatricia

  12. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet Hanford AdvisoryEnergy LessonsDIRECTIVES,DOEJimPatriciaLost

  13. Fusion Simulation Program

    SciTech Connect (OSTI)

    Project Staff

    2012-02-29

    Under this project, General Atomics (GA) was tasked to develop the experimental validation plans for two high priority ISAs, Boundary and Pedestal and Whole Device Modeling in collaboration with the theory, simulation and experimental communities. The following sections have been incorporated into the final FSP Program Plan (www.pppl.gov/fsp), which was delivered to the US Department of Energy (DOE). Additional deliverables by GA include guidance for validation, development of metrics to evaluate success and procedures for collaboration with experiments. These are also part of the final report.

  14. Hydrodynamic and hydromagnetic energy spectra from large eddy simulations

    E-Print Network [OSTI]

    N. E. L. Haugen; A. Brandenburg

    2006-06-29

    Direct and large eddy simulations of hydrodynamic and hydromagnetic turbulence have been performed in an attempt to isolate artifacts from real and possibly asymptotic features in the energy spectra. It is shown that in a hydrodynamic turbulence simulation with a Smagorinsky subgrid scale model using 512^3 meshpoints two important features of the 4096^3 simulation on the Earth simulator (Kaneda et al. 2003, Phys. Fluids 15, L21) are reproduced: a k^{-0.1} correction to the inertial range with a k^{-5/3} Kolmogorov slope and the form of the bottleneck just before the dissipative subrange. Furthermore, it is shown that, while a Smagorinsky-type model for the induction equation causes an artificial and unacceptable reduction in the dynamo efficiency, hyper-resistivity yields good agreement with direct simulations. In the large-scale part of the inertial range, an excess of the spectral magnetic energy over the spectral kinetic energy is confirmed. However, a trend towards spectral equipartition at smaller scales in the inertial range can be identified. With magnetic fields, no explicit bottleneck effect is seen.

  15. Staged direct injection diesel engine

    DOE Patents [OSTI]

    Baker, Quentin A. (San Antonio, TX)

    1985-01-01

    A diesel engine having staged injection for using lower cetane number fuels than No. 2 diesel fuel. The engine includes a main fuel injector and a pilot fuel injector. Pilot and main fuel may be the same fuel. The pilot injector injects from five to fifteen percent of the total fuel at timings from 20.degree. to 180.degree. BTDC depending upon the quantity of pilot fuel injected, the fuel cetane number and speed and load. The pilot fuel injector is directed toward the centerline of the diesel cylinder and at an angle toward the top of the piston, avoiding the walls of the cylinder. Stratification of the early injected pilot fuel is needed to reduce the fuel-air mixing rate, prevent loss of pilot fuel to quench zones, and keep the fuel-air mixture from becoming too fuel lean to become effective. In one embodiment, the pilot fuel injector includes a single hole for injection of the fuel and is directed at approximately 48.degree. below the head of the cylinder.

  16. Radial lean direct injection burner

    DOE Patents [OSTI]

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  17. Laparoscopic simulation interface

    DOE Patents [OSTI]

    Rosenberg, Louis B.

    2006-04-04

    A method and apparatus for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism provides two revolute degrees of freedom to an object about two axes of rotation. A linear axis member is coupled to the gimbal mechanism at the intersection of the two axes of rotation. The linear axis member is capable of being translated along a third axis to provide a third degree of freedom. The user object is coupled to the linear axis member and is thus translatable along the third axis so that the object can be moved along all three degrees of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a digital processing system. Capstan drive mechanisms transmit forces between the transducers and the object. The linear axis member can also be rotated about its lengthwise axis to provide a fourth degree of freedom, and, optionally, a floating gimbal mechanism is coupled to the linear axis member to provide fifth and sixth degrees of freedom to an object. Transducer sensors are associated with the fourth, fifth, and sixth degrees of freedom. The interface is well suited for simulations of medical procedures and simulations in which an object such as a stylus or a joystick is moved and manipulated by the user.

  18. Progress in Direct-Drive Inertial Confinement Fusion Research at the Laboratory for Laser Energetics

    SciTech Connect (OSTI)

    McCrory, R.L.; Meyerhofer, D.D.; Loucks, S.J.; Skupsky, S.; Betti, R.; Boehly, T.R.; Collins, T.J.B.; Craxton, R.S.; Delettrez, J.A.; Edgell, D.H.; Epstein, R.; Fletcher, K.A.; Freeman, C.; Frenje, J.A.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Igumenshchev, I.V.; Keck, R.L.; Kilkenny, J.D.; Knauer, J.P.; Li, C.K.; Marciante, J.; Marozas, J.a.; Marshall, F.J.; Maximov, A.V.; McKenty, P.W.; Morse, S.F.B.; Myatt, J.; Padalino, S.; Petrasso, R.D.; Radha, P.B.; Regan, S.P.; Sangster, T.C.; Seguin, F.H.; Seka, W.; Smalyuk, V.A.; Soures, J.M.; Stoeckl, C.; Yaakobi, B.; Zuegel, J.D.

    2006-06-28

    Direct-drive inertial confinement fusion (ICF) is expected to demonstrate high gain on the National Ignition Facility (NIF) in the next decade and is a leading candidate for inertial fusion energy production. The NIF will initially be configured for x-ray drive and with no beams placed at the target equator to provide a symmetric irradiation of a direct-drive capsule. LLE is developing the “polar-direct-drive” (PDD) approach that repoints beams toward the target equator. Initial 2-D simulations have shown ignition. A unique “Saturn-like” plastic ring around the equator refracts the laser light incident near the equator toward the target, improving the drive uniformity.

  19. Methodology for characterizing modeling and discretization uncertainties in computational simulation

    SciTech Connect (OSTI)

    ALVIN,KENNETH F.; OBERKAMPF,WILLIAM L.; RUTHERFORD,BRIAN M.; DIEGERT,KATHLEEN V.

    2000-03-01

    This research effort focuses on methodology for quantifying the effects of model uncertainty and discretization error on computational modeling and simulation. The work is directed towards developing methodologies which treat model form assumptions within an overall framework for uncertainty quantification, for the purpose of developing estimates of total prediction uncertainty. The present effort consists of work in three areas: framework development for sources of uncertainty and error in the modeling and simulation process which impact model structure; model uncertainty assessment and propagation through Bayesian inference methods; and discretization error estimation within the context of non-deterministic analysis.

  20. Simulating the Dynamic Coupling of Market and Physical System Operations

    SciTech Connect (OSTI)

    Widergren, Steven E.; Roop, Joseph M.; Guttromson, Ross T.; Huang, Zhenyu

    2004-06-01

    Abstract-As energy trading products cover shorter time periods and demand response programs move toward real-time pricing, financial market-based activity impacts ever more directly the physical operation of the system. To begin to understand the complex interactions between the market-driven operation signals, the engineered controlled schemes, and the laws of physics, new system modeling and simulation techniques must be explored. This discussion describes requirements for new simulation tools to address such market transaction control interactions and an approach to capture the dynamic coupling between energy markets and the physical operation of the power system appropriate for dispatcher reaction time frames.

  1. Neural Networks 24 (2011) 950960 Contents lists available at SciVerse ScienceDirect

    E-Print Network [OSTI]

    Fukai, Tomoki

    2011-01-01

    Neural Networks 24 (2011) 950­960 Contents lists available at SciVerse ScienceDirect Neural of a spiking neural network model of the basal ganglia circuitry using general purpose computing on graphics neural networks Real-time simulation GPGPUs Basal ganglia High-performance computing a b s t r a c t Real

  2. Evaluating aerosol direct radiative effects on global terrestrial ecosystem carbon dynamics from

    E-Print Network [OSTI]

    Zhuang, Qianlai

    loading normally induces lower solar energy arriving at the land surface whereas plant photosynthesis of diffuse solar radiation for plant carbon uptake. Comparing with direct-beam solar radiation, diffuse solar to quantify aerosol effects on downward solar radiation. Simulations with and without considering the aerosol

  3. Numerical modeling of extreme rogue waves generated by directional energy focusing

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    Numerical modeling of extreme rogue waves generated by directional energy focusing Christophe that contributes to the generation of extreme waves, also known as rogue waves, in the ocean. To simulate and analyze this phenomenon, we generate extreme waves in a 3D numerical wave tank (NWT), by specifying

  4. Direct laser initiation of PETN

    SciTech Connect (OSTI)

    Early, J. W. (James W.); Kennedy, J. E. (James E.)

    2001-01-01

    In the early 1970s Yang and Menichelli demonstrated that direct laser illumination of low-density secondary explosive prr:ssings through a transparent window could produce detonation. 'The energy requirement for threshold initiation of detonation was reduced when a thin metal coating of metal covered the side of the window against which the low-density explosive was pressed. We have obtained experimental results that are in general agreement with the results of Renllund, Stanton and Trott (1 989) and recent: work by Nagayama, hou and Nakahara (2001). We report exploration of the effects of laser beam diameter, PEiTN density and specific surface area, and thickness of a titanium coating on the window.

  5. Direct synthesis of calcium borohydride

    DOE Patents [OSTI]

    Ronnebro, Ewa Carin Ellinor (Dublin, CA); Majzoub, Eric H. (Pleasanton, CA)

    2009-10-27

    A method is disclosed for directly preparing an alkaline earth metal borohydride, i.e. Ca(BH.sub.4).sub.2, from the alkaline earth metal hydride and the alkaline earth metal boride. The borohydride thus prepared is doped with a small portion of a metal chloride catalyst compound, such as RuCl.sub.3, TiCl.sub.3, or a mixture of TiCl.sub.3 and palladium metal. The process provides for mechanically mixing the dry reagents under an inert atmosphere followed by charging the mixed materials with high pressure hydrogen at about 70 MPa while heating the mixture to about 400.degree. C. The method is relatively simple and inexpensive and provides reversible hydride compounds which are free of the usual contamination introduced by prior art wet chemical methods.

  6. Method for directional hydraulic fracturing

    DOE Patents [OSTI]

    Swanson, David E. (West St. Paul, MN); Daly, Daniel W. (Crystal, MN)

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  7. Direct synthesis of magnesium borohydride

    DOE Patents [OSTI]

    Ronnebro, Ewa Carin Ellinor (Kennewick, WA); Severa, Godwin (Honolulu, HI); Jensen, Craig M. (Kailua, HI)

    2012-04-03

    A method is disclosed for directly preparing an alkaline earth metal borohydride, i.e. Mg(BH.sub.4).sub.2, from the alkaline earth metal boride MgB.sub.2 by hydrogenating the MgB.sub.2 at an elevated temperature and pressure. The boride may also be doped with small amounts of a metal chloride catalyst such as TiCl.sub.3 and/or NiCl.sub.2. The process provides for charging MgB.sub.2 with high pressure hydrogen above at least 70 MPa while simultaneously heating the material to about 350.degree. C. to about 400.degree. C. The method is relatively simple and inexpensive and provides a reversible hydride compound having a hydrogen capacity of at least 11 wt %.

  8. Laboratory directed research and development

    SciTech Connect (OSTI)

    Not Available

    1991-11-15

    The purposes of Argonne's Laboratory Directed Research and Development (LDRD) Program are to encourage the development of novel concepts, enhance the Laboratory's R D capabilities, and further the development of its strategic initiatives. Among the aims of the projects supported by the Program are establishment of engineering proof-of-principle''; development of an instrumental prototype, method, or system; or discovery in fundamental science. Several of these project are closely associated with major strategic thrusts of the Laboratory as described in Argonne's Five Year Institutional Plan, although the scientific implications of the achieved results extend well beyond Laboratory plans and objectives. The projects supported by the Program are distributed across the major programmatic areas at Argonne. Areas of emphasis are (1) advanced accelerator and detector technology, (2) x-ray techniques in biological and physical sciences, (3) advanced reactor technology, (4) materials science, computational science, biological sciences and environmental sciences. Individual reports summarizing the purpose, approach, and results of projects are presented.

  9. Technical Standards,DOE Standards and Corresponding Directives...

    Broader source: Energy.gov (indexed) [DOE]

    Directives Crosswalk DOE Standards and Corresponding Directives Crosswalk table Technical Standards,DOE Standards and Corresponding Directives Crosswalk More Documents &...

  10. Distributed Energy Technology Simulator: Microturbine Demonstration...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Simulator: Microturbine Demonstration, October 2001 Distributed Energy Technology Simulator: Microturbine Demonstration, October 2001 This 2001 paper discusses the National Rural...

  11. Multidimensional simulation and chemical kinetics development...

    Energy Savers [EERE]

    Multidimensional simulation and chemical kinetics development for high efficiency clean combustion engines Multidimensional simulation and chemical kinetics development for high...

  12. Plain Language Disclosure for Direct Subsidized Loans and Direct Unsubsidized Loans William D. Ford Federal Direct Loan Program

    E-Print Network [OSTI]

    Royer, Dana

    Plain Language Disclosure for Direct Subsidized Loans and Direct Unsubsidized Loans William D. Ford Subsidized Loan and/or Direct Unsubsidized Loan to help cover the costs of your education. This Plain to separate loans made under the MPN depending on whether the loan is subsidized or unsubsidized, when

  13. Investigations of Solar Prominence Dynamics Using Laboratory Simulations

    SciTech Connect (OSTI)

    Paul M Bellan

    2008-05-28

    Laboratory experiments simulating many of the dynamical features of solar coronal loops have been carried out. These experiments manifest collimation, kinking, jet flows, and S-shapes. Diagnostics include high-speed photography and x-ray detectors. Two loops having opposite or the same magnetic helicity polarities have been merged and it is found that counter-helicity merging provides much greater x-ray emission. A non-MHD particle orbit instability has been discovered whereby ions going in the opposite direction of the current flow direction can be ejected from a magnetic flux tube.

  14. Non-detonable explosive simulators

    DOE Patents [OSTI]

    Simpson, R.L.; Pruneda, C.O.

    1994-11-01

    A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules. 5 figs.

  15. Lubricant characterization by molecular simulation

    SciTech Connect (OSTI)

    Moore, J.D.; Cui, S.T.; Cummings, P.T.; Cochran, H.D.

    1997-12-01

    The authors have reported the calculation of the kinematic viscosity index of squalane from nonequilibrium molecular dynamics simulations. This represents the first accurate quantitative prediction of this measure of lubricant performance by molecular simulation. Using the same general alkane potential model, this computational approach offers the possibility of predicting the performance of potential lubricants prior to synthesis. Consequently, molecular simulation is poised to become an important tool for future lubricant development.

  16. Non-detonable explosive simulators

    DOE Patents [OSTI]

    Simpson, Randall L. (Livermore, CA); Pruneda, Cesar O. (Livermore, CA)

    1994-01-01

    A simulator which is chemically equivalent to an explosive, but is not detonable. The simulator has particular use in the training of explosives detecting dogs and calibrating sensitive analytical instruments. The explosive simulants may be fabricated by different techniques, a first involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and the second involves coating inert beads with thin layers of explosive molecules.

  17. BERNAS ION SOURCE DISCHARGE SIMULATION

    SciTech Connect (OSTI)

    RUDSKOY,I.; KULEVOY, T.V.; PETRENKO, S.V.; KUIBEDA, R.P.; SELEZNEV, D.N.; PERSHIN, V.I.; HERSHCOVITCH, A.; JOHNSON, B.M.; GUSHENETS, V.I.; OKS, E.M.; POOLE, H.J.

    2007-08-26

    The joint research and development program is continued to develop steady-state ion source of decaborane beam for ion implantation industry. Bemas ion source is the wide used ion source for ion implantation industry. The new simulation code was developed for the Bemas ion source discharge simulation. We present first results of the simulation for several materials interested in semiconductors. As well the comparison of results obtained with experimental data obtained at the ITEP ion source test-bench is presented.

  18. Physical limits on cellular directional mechanosensing

    E-Print Network [OSTI]

    Bouffanais, Roland

    Many eukaryotic cells are able to perform directional mechanosensing by directly measuring minute spatial differences in the mechanical stress on their membranes. Here, we explore the limits of a single mechanosensitive ...

  19. BIOMEDICAL MATHEMATICS: Promising Directions in Imaging,

    E-Print Network [OSTI]

    Censor, Yair

    BIOMEDICAL MATHEMATICS: Promising Directions in Imaging, Therapy Planning, and Inverse Problems #12;BIOMEDICAL MATHEMATICS: Promising Directions in Imaging, Therapy Planning, and Inverse Problems Yair Censor, Ming Jiang, Ge Wang Editors The Huangguoshu International Interdisciplinary Conference on Biomedical

  20. Power Plant Modeling and Simulation

    ScienceCinema (OSTI)

    None

    2010-01-08

    The National Energy Technology Laboratory's Office of Research and Development provides open source tools and expetise for modeling and simulating power plants and carbon sequestration technologies.

  1. Power Plant Modeling and Simulation

    SciTech Connect (OSTI)

    2008-07-21

    The National Energy Technology Laboratory's Office of Research and Development provides open source tools and expetise for modeling and simulating power plants and carbon sequestration technologies.

  2. Direct and Large-Eddy Simulations of a Turbulent Flow with Effusion

    E-Print Network [OSTI]

    Nicoud, Franck

    to be cooled. One possibility often chosen in gas turbines is to use multiperforated walls to produce in actual gas turbines make any measurement very challenging. · the number of holes make accurate test rig. 1 Introduction In almost all the systems where combustion occurs, solid boundaries need

  3. INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES The Direct Simulation Monte-Carlo technique

    E-Print Network [OSTI]

    Riabov, Vladimir V.

    force between side-by-side plates and cylinders, dependence of drag on torus radii ratio, and reverse, two side-by-side plates and cylinders, sphere, torus, and rotating cylinder. Important kinetic effects found in the cases of plates, wedges, cones, spheres, and cylinders [4- 13]. In the present paper

  4. Direct simulation and deterministic prediction of large-scale nonlinear ocean wave-field

    E-Print Network [OSTI]

    Wu, Guangyu, 1972-

    2004-01-01

    Despite its coarse approximation of physics, the phase-averaged wave spectrum model has been the only type of tool available for ocean wave prediction in the past 60 years. With the rapid advances in sensing technology, ...

  5. Direct numerical simulation of electroconvective instability and hysteretic current-voltage response of a permselective membrane

    E-Print Network [OSTI]

    Pham, Van Sang

    We present a systematic, multiscale, fully detailed numerical modeling for dynamics of fluid flow and ion transport covering Ohmic, limiting, and overlimiting current regimes in conductance of ion-selective membrane. By ...

  6. submitted to ApJ Direct Numerical Simulations of Type Ia Supernovae Flames I

    E-Print Network [OSTI]

    Bell, John B.

    for C/O thermonuclear flames at conditions relevant to the late stages of a Type Ia supernova explosion and results relevant for thermonuclear flames. Sivashinsky (1977) and Michelson & Sivashinsky (1977) studied

  7. Direct Numerical Simulations of Type Ia Supernovae Flames II: The Rayleigh-Taylor Instability

    E-Print Network [OSTI]

    Bell, John B.

    Accelerating a thermonuclear flame to a large fraction of the speed of sound (possibly supersonic) is one

  8. DIRECT AND LARGE EDDY SIMULATIONS OF A BOTTOM EKMAN LAYER UNDER AN EXTERNAL STRATIFICATION

    E-Print Network [OSTI]

    Taylor, John R.

    be approximated as an adiabatic boundary with the excep- tion of isolated geothermal hotspots. However stratification and vertical shear, both with and without a surface heat flux. They used their results

  9. Simulation and Control of Dynamic Directed Self-assembly of Nanostructures

    E-Print Network [OSTI]

    ............................................................ George Stephanopoulos Arthur D. Little Professor of Chemical Engineering Thesis Supervisor Certified by by ........................................................... Richard D. Braatz Edwin R. Gilliland Professor of Chemical Engineering Chairman, Committee for Graduate

  10. A numerical framework for the direct simulation of solid-fluid systems

    E-Print Network [OSTI]

    Cook, Benjamin Koger, 1965-

    2001-01-01

    Our understanding of solid-fluid dynamics has been severely limited by the nonexistence of a high-fidelity modeling capability for these multiphase systems. Continuum modeling approaches overlook the microscale solid-fluid ...

  11. A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion 

    E-Print Network [OSTI]

    Xue, Xingyu 1985-

    2012-11-15

    -ignition radicals, start of combustion, and eventual heat release. These mechanisms are described based on the current understanding and knowledge of the diesel engine combustion acquired through advanced laser-based diagnostics. Six zones are developed to take...

  12. Instability of High Mach Number Poiseuille (Channel) Flow: Linear Analysis and Direct Numerical Simulations 

    E-Print Network [OSTI]

    Xie, Zhimin

    2014-08-06

    is examined. Grid resolution and time-step convergence studies are performed over the range of Mach numbers of interest. The next study establishes the stability characteristics at very high and very low Mach number limits. While stability at low Mach number...

  13. Direct Numerical Simulations of Interfacial Turbulence at Low Froude and Weber Numbers 

    E-Print Network [OSTI]

    Zhang, Qi

    2014-05-22

    that for this detection method the effects of ubiquitous surfactants (surface free agents) to the subsurface turbulence should also be considered. In the case when the wind stress at the surface is far less significant than the buoyancy force in the water phase, the cool...

  14. American Institute of Aeronautics and Astronautics Direct Simulation of Surface Roughness Effects with RANS

    E-Print Network [OSTI]

    Wang, Zhi Jian "ZJ"

    of land-based gas turbines operate in a particularly harsh environment. All surfaces such as blades, vanes, which hastens further material degradation. In order to estimate the service life of turbine blades, pitting, and spallation of thermal-barrier coatings depend on the environment from which the air

  15. Direct numerical simulations of multiphase flow with applications to basaltic volcanism and planetary evolution

    E-Print Network [OSTI]

    Suckale, Jenny

    2011-01-01

    Multiphase flows are an essential component of natural systems: They affect the explosivity of volcanic eruptions, shape the landscape of terrestrial planets, and govern subsurface flow in hydrocarbon reservoirs. Advancing ...

  16. Direct numerical simulation of a reacting turbulent channel flow with thermo-chemical ablation

    E-Print Network [OSTI]

    Boyer, Edmond

    in the material itself); 3) sublimation of the material at high temperature; 4) mechan- ical erosion due species of the combustion products such as H2O, CO2, H2 or OH. As a consequence, the heterogeneous surface, the use of high energy solid propellant generates an hostile environment and the nozzle structure

  17. Stochastic Modeling and Direct Simulation of the Diffusion Media for Polymer Electrolyte Fuel Cells

    E-Print Network [OSTI]

    Schmidt, Volker

    Cells Yun Wang* and Xuhui Feng Renewable Energy Resources Lab (RERL) and National Fuel Cell Research the stochastic-model-based reconstruction of the gas diffusion layer (GDL) of polymer electrolyte fuel cells on pore-level transport and scrutinize the macroscopic approach vastly adopted in current fuel cell

  18. Large Eddy Simulation of Supersonic Combustion using Direct Quadrature Method of Moments

    E-Print Network [OSTI]

    Raman, Venkat

    be used. Transport of the joint filtered density function (FDF) of the thermochemical composition vector are based on a conserved scalar approach, where the gas- phase thermochemical state is mapped through the enthalpy evolution depends on the local pressure and velocity fields in supersonic flows, the gas

  19. Direct Numerical Simulation of Surfactant-Stabilized Emulsions Morphology and Shear Viscosity in Starting Shear Flow

    SciTech Connect (OSTI)

    Roar Skartlien; Espen Sollum; Andreas Akselsen; Paul Meakin

    2012-07-01

    A 3D lattice Boltzmann model for two-phase flow with amphiphilic surfactant was used to investigate the evolution of emulsion morphology and shear stress in starting shear flow. The interfacial contributions were analyzed for low and high volume fractions and varying surfactant activity. A transient viscoelastic contribution to the emulsion rheology under constant strain rate conditions was attributed to the interfacial stress. For droplet volume fractions below 0.3 and an average capillary number of about 0.25, highly elliptical droplets formed. Consistent with affine deformation models, gradual elongation of the droplets increased the shear stress at early times and reduced it at later times. Lower interfacial tension with increased surfactant activity counterbalanced the effect of increased interfacial area, and the net shear stress did not change significantly. For higher volume fractions, co-continuous phases with a complex topology were formed. The surfactant decreased the interfacial shear stress due mainly to advection of surfactant to higher curvature areas. Our results are in qualitative agreement with experimental data for polymer blends in terms of transient interfacial stresses and limited enhancement of the emulsion viscosity at larger volume fractions where the phases are co-continuous.

  20. DYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION

    E-Print Network [OSTI]

    the completion of the 500 m2 SG4 dish concentrator system in 2009 [1], the Solar Thermal Group at the Australian to an electrical generator, a cooling tower and associated piping. The steam system is installed in a shipping to the water tank for reuse. The thermal output of the system exceeds the capacity of the steam engine

  1. Direct Numerical Simulation of Autoignition in a Jet in a Cross...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    air in a laboratory-scale configuration. Detailed description of chemistry and molecular transport will be used to investigate the flow and scalar fields under cold and reactive...

  2. Study of multi-component fuel premixed combustion using direct numerical simulation

    E-Print Network [OSTI]

    Nikolaou, Zacharias M.

    2014-04-29

    on a daily basis during the course of this research. I would also like to acknowledge the funding through the Low Car- bon Energy University Alliance Programme supported by Tsinghua University, China, and also the educational grant through the A...

  3. Direct numerical simulation and subgrid analysis of a transitional droplet laden mixing layer

    E-Print Network [OSTI]

    Miller, Richard S.

    and liquid droplet flows; e.g., pulverized coal combustion, spray painting, spray combustion, atomization

  4. Measuring the black hole spin direction in 3D Cartesian numerical relativity simulations

    E-Print Network [OSTI]

    Vassilios Mewes; José A. Font; Pedro J. Montero

    2015-05-27

    We show that the so-called flat-space rotational Killing vector method for measuring the Cartesian components of a black hole spin can be derived from the surface integral of Weinberg's pseudotensor over the apparent horizon surface when using Gaussian normal coordinates in the integration. Moreover, the integration of the pseudotensor in this gauge yields the Komar angular momentum integral in a foliation adapted to the axisymmetry of the spacetime. As a result, the method does not explicitly depend on the evolved lapse $\\alpha$ and shift $\\beta^i$ on the respective timeslice, as they are fixed to Gaussian normal coordinates, while leaving the coordinate labels of the spatial metric $\\gamma_{ij}$ and the extrinsic curvature $K_{ij}$ unchanged. Such gauge fixing endows the method with coordinate invariance, which is not present in integral expressions using Weinberg's pseudotensor, as they normally rely on the explicit use of Cartesian coordinates.

  5. Strategic Directions for Hydrogen Delivery Workshop Proceedings

    Broader source: Energy.gov [DOE]

    Proceedings from the Strategic Directions for Hydrogen Delivery Workshop held May 7-8, 2003 in Washington, DC. Author: Energetics

  6. Directional detection of galactic dark matter

    E-Print Network [OSTI]

    Mayet, F; Santos, D

    2012-01-01

    Directional detection is a promising Dark Matter search strategy. Taking advantage on the rotation of the Solar system around the galactic center through the Dark Matter halo, it allows to show a direction dependence of WIMP events that may be a powerful tool to identify genuine WIMP events as such. Directional detection strategy requires the simultaneous measurement of the energy and the 3D track of low energy recoils, which is a common challenge for all current projects of directional detectors.

  7. Extension of DOE Directives on Security

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-12-31

    This Notice extends 15 Office of Security and Emergency Operation directives that have expired or will expire until December 31, 2001. This Notice will remain in effect until its expiration date or until new/revised directives are published. The following statement will be added to the summary of the extended directives-DOE N 251.40, dated 5/3/01, extends this directive until 12/31/01.

  8. Theoretical prospects for directional WIMP detection

    E-Print Network [OSTI]

    O'Hare, Ciaran A J

    2015-01-01

    Direct detection of dark matter with directional sensitivity is a promising concept for improving the search for weakly interacting massive particles. With information on the direction of WIMP induced nuclear recoils one has access to the full 3-dimensional velocity distribution of the local dark matter halo and thus a potential avenue for studying WIMP astrophysics. Furthermore the unique angular signature of the WIMP recoil distribution provides a crucial discriminant from neutrinos which currently represent the ultimate background to direct detection experiments.

  9. Theoretical prospects for directional WIMP detection

    E-Print Network [OSTI]

    Ciaran A. J. O'Hare

    2015-10-14

    Direct detection of dark matter with directional sensitivity is a promising concept for improving the search for weakly interacting massive particles. With information on the direction of WIMP induced nuclear recoils one has access to the full 3-dimensional velocity distribution of the local dark matter halo and thus a potential avenue for studying WIMP astrophysics. Furthermore the unique angular signature of the WIMP recoil distribution provides a crucial discriminant from neutrinos which currently represent the ultimate background to direct detection experiments.

  10. Hydrothermal industrialization: direct heat development. Final report

    SciTech Connect (OSTI)

    Not Available

    1982-05-01

    A description of hydrothermal resources suitable for direct applications, their associated temperatures, geographic distribution and developable capacity are given. An overview of the hydrothermal direct-heat development infrastructure is presented. Development activity is highlighted by examining known and planned geothermal direct-use applications. Underlying assumptions and results for three studies conducted to determine direct-use market penetration of geothermal energy are discussed.

  11. Project Profile: Direct Supercritical Carbon Dioxide Receiver...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Receiver Development Project Profile: Direct Supercritical Carbon Dioxide Receiver Development National Renewable Energy Laboratory logo The National Renewable Energy...

  12. Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vehicle Technologies Office Merit Review 2015: Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine Development Vehicle Technologies Office Merit Review 2014:...

  13. Parallel Computing Environments and Methods for Power Distribution System Simulation

    SciTech Connect (OSTI)

    Lu, Ning; Taylor, Zachary T.; Chassin, David P.; Guttromson, Ross T.; Studham, Scott S.

    2005-11-10

    The development of cost-effective high-performance parallel computing on multi-processor super computers makes it attractive to port excessively time consuming simulation software from personal computers (PC) to super computes. The power distribution system simulator (PDSS) takes a bottom-up approach and simulates load at appliance level, where detailed thermal models for appliances are used. This approach works well for a small power distribution system consisting of a few thousand appliances. When the number of appliances increases, the simulation uses up the PC memory and its run time increases to a point where the approach is no longer feasible to model a practical large power distribution system. This paper presents an effort made to port a PC-based power distribution system simulator (PDSS) to a 128-processor shared-memory super computer. The paper offers an overview of the parallel computing environment and a description of the modification made to the PDSS model. The performances of the PDSS running on a standalone PC and on the super computer are compared. Future research direction of utilizing parallel computing in the power distribution system simulation is also addressed.

  14. SIMULATING PROTOSTELLAR JETS SIMULTANEOUSLY AT LAUNCHING AND OBSERVATIONAL SCALES

    SciTech Connect (OSTI)

    Ramsey, Jon P.; Clarke, David A. [Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3 (Canada)

    2011-02-10

    We present the first 2.5-dimensional magnetohydrodynamic (MHD) simulations of protostellar jets that include both the region in which the jet is launched magnetocentrifugally at scale lengths <0.1 AU and where the propagating jet is observed at scale lengths >10{sup 3} AU. These simulations, performed with the new adaptive mesh refinement MHD code AZEuS, reveal interesting relationships between conditions at the disk surface, such as the magnetic field strength, and direct observables such as proper motion, jet rotation, jet radius, and mass flux. By comparing these quantities with observed values, we present direct numerical evidence that the magnetocentrifugal launching mechanism is capable, by itself, of launching realistic protostellar jets.

  15. A comparison of techniques for simulating set-up error and uncertainty in head and neck IMRT

    SciTech Connect (OSTI)

    Ploquin, Nicolas; Kay, Ian; Rangel-Baltazar, Alejandra; Lau, Harold; Dunscombe, Peter [Tom Baker Cancer Centre, Department of Medical Physics, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada) and University of Calgary, Department of Physics and Astronomy, 2500 University Drive, Calgary, Alberta, T2N 1N4 (Canada); Tom Baker Cancer Centre, Department of Medical Physics, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada) and University of Calgary, Department of Physics and Astronomy, 2500 University Drive, Calgary, Alberta, T2N 1N4 (Canada) and University of Calgary, Department of Oncology, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada); Tom Baker Cancer Centre, Department of Medical Physics, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada) and University of Calgary, Department of Physics and Astronomy, 2500 University Drive, Calgary, Alberta, T2N 1N4 (Canada); Tom Baker Cancer Centre, Department of Radiation Oncology, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada) and University of Calgary, Department of Oncology, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada); Tom Baker Cancer Centre, Department of Medical Physics, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada) and University of Calgary, Department of Physics and Astronomy, 2500 University Drive, Calgary, Alberta, T2N 1N4 (Canada) and University of Calgary, Department of Oncology, 1331-29 Street NW, Calgary, Alberta, T2N 4N2 (Canada)

    2006-09-15

    We have compared four computational methods for quantifying the effect of set-up error and uncertainty on delivered doses to targets and organs at risk in the intensity modulated radiation therapy treatment of head and neck cancer. These four methods were direct simulation, simple convolution, plus two modified convolution approaches. Discrepancies of up to 20% in the equivalent uniform dose (EUD) between direct simulation and simple convolution were estimated for the relatively superficial parotid gland at a systematic set-up error of 6 mm standard deviation and a random uncertainty of 2 mm standard deviation. Truncated convolution agreed with direct simulation to within 6% for all situations studied. However, of the four methods, only direct simulation can quantify the range of outcomes (EUD) associated with a finite number of courses and fractions. Our results are particularly relevant to the design of dose escalation studies in head and neck cancer.

  16. An analysis of delamination in composite material notched tensile beams 

    E-Print Network [OSTI]

    Tangirala, Prema Kumar

    1991-01-01

    . The notched tensile beam (NTB) specimen Page 2. Comparison with analytical results (adapted from [2]) . 3. The three basic modes of cracking opening . 4. The cracked lap shear (CLS) specimen. 5. Tapered CLS specimen with adhesive layer, . 13 6. Double... for the cases studied was to decrease the total G, with the reductions ranging from 5% to 13%. Simons [3] investigated the closed form analytical treatment of delamination strain energy release rates for the NTB specimen with uni-directional laminates. He...

  17. Air breathing direct methanol fuel cell

    DOE Patents [OSTI]

    Ren, Xiaoming (Los Alamos, NM)

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  18. Micro Fuel Cells Direct Methanol Fuel Cells

    E-Print Network [OSTI]

    Micro Fuel Cells TM Direct Methanol Fuel Cells for Portable Power A Fuel Cell System Developer-17, 2002 Phoenix, Arizona #12;Micro Fuel Cells Direct Methanol Fuel Cells for Portable Power Outline (1 Energy Content (Wh) Volume(cm^3) Li-Ion Battery DMFC #12;Direct Methanol Fuel Cell Technology

  19. Simulation of Fusion Plasmas

    ScienceCinema (OSTI)

    Holland, Chris [UC San Diego, San Diego, California, United States

    2010-01-08

    The upcoming ITER experiment (www.iter.org) represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the ?burning plasma? regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

  20. Exploiting simultaneous observational constraints on mass and absorption to estimate the global direct radiative forcing of black carbon and brown carbon

    E-Print Network [OSTI]

    Schwarz, J. P.

    Atmospheric black carbon (BC) is a leading climate warming agent, yet uncertainties on the global direct radiative forcing (DRF) remain large. Here we expand a global model simulation (GEOS-Chem) of BC to include the ...

  1. Polar-direct-drive experiments on the National Ignition Facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hohenberger, M.; Radha, P. B.; Myatt, J. F.; LePape, S.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; et al

    2015-05-11

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beammore »geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D? gas were imploded with total drive energies ranging from ~500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 10¹? to 1.2 10¹?W/cm². Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.« less

  2. Polar-direct-drive experiments on the National Ignition Facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hohenberger, M. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000258879711); Radha, P. B. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Myatt, J. F. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); LePape, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marozas, J. A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Marshall, F. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Michel, D. T. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000166894359); Regan, S. P. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Seka, W. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Shvydky, A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Sangster, T. C. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000340402672); Bates, J. W. [U. S. Naval Research Lab., Washington, DC (United States)] (ORCID:0000000188087240); Betti, R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Boehly, T. R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Bonino, M. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Casey, D. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Collins, T. J. B. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Craxton, R. S. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000158858227); Delettrez, J. A. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Edgell, D. H. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Epstein, R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)] (ORCID:0000000340628444); Fiksel, G. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Fitzsimmons, P. [General Atomics, San Diego, CA (United States); Frenje, J. A. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)] (ORCID:0000000168460378); Froula, D. H. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Goncharov, V. N. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Harding, D. R. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kalantar, D. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Karasik, M. [U. S. Naval Research Lab., Washington, DC (United States); Kessler, T. J. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kilkenny, J. D. [General Atomics, San Diego, CA (United States); Knauer, J. P. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Kurz, C. [General Atomics, San Diego, CA (United States); Lafon, M. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); LaFortune, K. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacGowan, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mackinnon, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacPhee, A. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000341604479); McCrory, R. L. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); McKenty, P. W. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States); Meeker, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Meyerhofer, D. D. [Lab. for Laser Energetics, University of Rochester, Rochester, NY (United States)

    2015-05-01

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D? gas were imploded with total drive energies ranging from ~500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 10¹? to 1.2 10¹?W/cm². Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

  3. Polar-direct-drive experiments on the national ignition facilitya)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hohenberger, M.; Radha,, P. B.; Myatt, J. F.; LePape, S.; Marozas,, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; et al

    2015-05-01

    To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beammore »geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D? gas were imploded with total drive energies ranging from ~500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 x 10¹? to 1.2 x 10¹?W/cm². Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.« less

  4. Numerical simulations of the decay of primordial magnetic turbulence

    SciTech Connect (OSTI)

    Kahniashvili, Tina [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, ON P3E 2C (Canada); Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Brandenburg, Axel [Nordita, AlbaNova University Center, Roslagstullsbacken 23, 10691 Stockholm (Sweden); Department of Astronomy, Stockholm University, SE 10691 Stockholm (Sweden); Tevzadze, Alexander G. [Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Faculty of Exact and Natural Sciences, Tbilisi State University, 1 Chavchavadze Avenue Tbilisi, GE-0128 (Georgia); Ratra, Bharat [Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, Kansas 66506 (United States)

    2010-06-15

    We perform direct numerical simulations of forced and freely decaying 3D magnetohydrodynamic turbulence in order to model magnetic field evolution during cosmological phase transitions in the early Universe. Our approach assumes the existence of a magnetic field generated either by a process during inflation or shortly thereafter, or by bubble collisions during a phase transition. We show that the final configuration of the magnetic field depends on the initial conditions, while the velocity field is nearly independent of initial conditions.

  5. Low backlash direct drive actuator

    DOE Patents [OSTI]

    Kuklo, T.C.

    1994-10-25

    A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw. 10 figs.

  6. Direct detector for terahertz radiation

    DOE Patents [OSTI]

    Wanke, Michael C. (Albuquerque, NM); Lee, Mark (Albuquerque, NM); Shaner, Eric A. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA)

    2008-09-02

    A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

  7. Geothermal Direct Use Technology & Marketplace Workshop Summary

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    seismicity; and developing utilization models (utilizing Geothermal Energy for the Production of Heat and Electricity Economically Simulated (GEOPHIRES) software) that are...

  8. Fast computation algorithms for speckle pattern simulation

    SciTech Connect (OSTI)

    Nascov, Victor; Samoil?, Cornel; Ursu?iu, Doru [Transylvania University of Braov (Romania)

    2013-11-13

    We present our development of a series of efficient computation algorithms, generally usable to calculate light diffraction and particularly for speckle pattern simulation. We use mainly the scalar diffraction theory in the form of Rayleigh-Sommerfeld diffraction formula and its Fresnel approximation. Our algorithms are based on a special form of the convolution theorem and the Fast Fourier Transform. They are able to evaluate the diffraction formula much faster than by direct computation and we have circumvented the restrictions regarding the relative sizes of the input and output domains, met on commonly used procedures. Moreover, the input and output planes can be tilted each to other and the output domain can be off-axis shifted.

  9. Electric heater for nuclear fuel rod simulators

    DOE Patents [OSTI]

    McCulloch, Reginald W. (Knoxville, TN); Morgan, Jr., Chester S. (Oak Ridge, TN); Dial, Ralph E. (Concord, TN)

    1982-01-01

    The present invention is directed to an electric cartridge-type heater for use as a simulator for a nuclear fuel pin in reactor studies. The heater comprises an elongated cylindrical housing containing a longitudinally extending helically wound heating element with the heating element radially inwardly separated from the housing. Crushed cold-pressed preforms of boron nitride electrically insulate the heating element from the housing while providing good thermal conductivity. Crushed cold-pressed preforms of magnesia or a magnesia-15 percent boron nitride mixture are disposed in the cavity of the helical heating element. The coefficient of thermal expansion of the magnesia or the magnesia-boron nitride mixture is higher than that of the boron nitride disposed about the heating element for urging the boron nitride radially outwardly against the housing during elevated temperatures to assure adequate thermal contact between the housing and the boron nitride.

  10. Sensitivity technologies for large scale simulation.

    SciTech Connect (OSTI)

    Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias; Wilcox, Lucas C.; Hill, Judith C.; Ghattas, Omar; Berggren, Martin Olof; Akcelik, Volkan; Ober, Curtis Curry; van Bloemen Waanders, Bart Gustaaf; Keiter, Eric Richard

    2005-01-01

    Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective through the development of hybrid automatic differentiation tools, standard linear algebra interfaces for numerical algorithms, time domain decomposition algorithms and two level Newton methods. We attempt to accomplish the second goal by presenting the results of several case studies in which direct sensitivities and adjoint methods have been effectively applied, in addition to an investigation of h-p adaptivity using adjoint based a posteriori error estimation. A mathematical overview is provided of direct sensitivities and adjoint methods for both steady state and transient simulations. Two case studies are presented to demonstrate the utility of these methods. A direct sensitivity method is implemented to solve a source inversion problem for steady state internal flows subject to convection diffusion. Real time performance is achieved using novel decomposition into offline and online calculations. Adjoint methods are used to reconstruct initial conditions of a contamination event in an external flow. We demonstrate an adjoint based transient solution. In addition, we investigated time domain decomposition algorithms in an attempt to improve the efficiency of transient simulations. Because derivative calculations are at the root of sensitivity calculations, we have developed hybrid automatic differentiation methods and implemented this approach for shape optimization for gas dynamics using the Euler equations. The hybrid automatic differentiation method was applied to a first order approximation of the Euler equations and used as a preconditioner. In comparison to other methods, the AD preconditioner showed better convergence behavior. Our ultimate target is to perform shape optimization and hp adaptivity using adjoint formulations in the Premo compressible fluid flow simulator. A mathematical formulation for mixed-level simulation algorithms has been developed where different physics interact at potentially different spatial resolutions in a single domain. To minimize the implementation effort, explicit solution methods can be considered, however, implicit methods are preferred if computational efficiency is of high priority. We present the use of a partial elimination nonlinear solver technique to solve these mixed level problems and show how these formulation are closely coupled to intrusive optimization approaches and sensitivity analyses. Production codes are typically not designed for sensitivity analysis or large scale optimization. The implementation of our optimization libraries into multiple production simulation codes in which each code has their own linear algebra interface becomes an intractable problem. In an attempt to streamline this task, we have developed a standard interface between the numerical algorithm (such as optimization) and the underlying linear algebra. These interfaces (TSFCore and TSFCoreNonlin) have been adopted by the Trilinos framework and the goal is to promote the use of these interfaces especially with new developments. Finally, an adjoint based a posteriori error estimator has been developed for discontinuous Galerkin discretization of Poisson's equation. The goal is to investigate other ways to leverage the adjoint calculations and we show how the convergence of the forward problem can be improved by adapting the grid using adjoint-based error estimates. Error estimation is usually conducted with continuous adjoints but if discrete adjoints are available it may be possible to reuse the discrete version for error estimation. We investigate the advantages and disadvantages of continuous and discre

  11. Molecular Dynamics Simulation of Binary Fluid in a Nanochannel

    SciTech Connect (OSTI)

    Mullick, Shanta; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University, SummerHill, Shimla - 171005 (India); Pathania, Y. [Chitkara University, Atal Shiksha Kunj, Atal Nagar, Barotiwala, Dist Solan, Himachal Pradesh - 174103 (India)

    2011-12-12

    This paper presents the results from a molecular dynamics simulation of binary fluid (mixture of argon and krypton) in the nanochannel flow. The computational software LAMMPS is used for carrying out the molecular dynamics simulations. Binary fluids of argon and krypton with varying concentration of atom species were taken for two densities 0.65 and 0.45. The fluid flow takes place between two parallel plates and is bounded by horizontal walls in one direction and periodic boundary conditions are imposed in the other two directions. To drive the flow, a constant force is applied in one direction. Each fluid atom interacts with other fluid atoms and wall atoms through Week-Chandler-Anderson (WCA) potential. The velocity profile has been looked at for three nanochannel widths i.e for 12{sigma}, 14{sigma} and 16{sigma} and also for the different concentration of two species. The velocity profile of the binary fluid predicted by the simulations agrees with the quadratic shape of the analytical solution of a Poiseuille flow in continuum theory.

  12. On the number density of "direct collapse" black hole seeds

    E-Print Network [OSTI]

    Habouzit, Melanie; Latif, Muhammad; Dubois, Yohan; Peirani, Sebastien

    2016-01-01

    Supermassive black holes (BHs) of millions solar masses and above reside in the center of most local galaxies, but they also power active galactic nuclei and quasars, detected up to z=7. This observational evidence puts strong constraints on the BH growth and the mass of the first BH seeds. The scenario of "direct collapse" is very appealing as it leads to the formation of large mass BH seeds in the range 10^4-10^6 Msun, which eases explaining how quasars at z=6-7 are powered by BHs with masses >10^9 Msun. Direct collapse, however, appears to be rare, as the conditions required by the scenario are that gas is metal-free, the presence of a strong photo-dissociating Lyman-Werner flux, and large inflows of gas at the center of the halo, sustained for 10-100 Myr. We performed several cosmological hydrodynamical simulations that cover a large range of box sizes and resolutions, thus allowing us to understand the impact of several physical processes on the distribution of direct collapse BHs. We identify halos wher...

  13. Cowgame: animal breeding simulation software 

    E-Print Network [OSTI]

    Kleibrink, Kevin Michael

    1997-01-01

    are simulated for each anii-nal. Five sires and 50 dams are simulated for each herd. A maximum of 125 herds can be developed at once. The five sires are mated to 10 dams each to produce offspring in the first generation. The herd owner then enters selection...

  14. CONSTRUCTING VIRTUAL HUMAN LIFE SIMULATIONS

    E-Print Network [OSTI]

    Kallmann, Marcelo

    , Virtual Environments, Behavioral Animation, Object Interaction, Python. 1. INTRODUCTION Virtual humanCONSTRUCTING VIRTUAL HUMAN LIFE SIMULATIONS Marcelo Kallmann, Etienne de Sevin and Daniel Thalmann human life simulations. Our main goal is to have virtual human actors living and working autonomously

  15. Simulation of open quantum systems

    E-Print Network [OSTI]

    Florian Mintert; Eric J. Heller

    2008-03-27

    We present an approach for the semiclassical treatment of open quantum systems. An expansion into localized states allows restriction of a simulation to a fraction of the environment that is located within a predefined vicinity of the system. Adding and dropping environmental particles during the simulation yields an effective reduction of the size of the system that is being treated.

  16. Local community extraction in directed networks

    E-Print Network [OSTI]

    Ning, Xuemei; Zhang, Shihua

    2015-01-01

    Network is a simple but powerful representation of real-world complex systems. Network community analysis has become an invaluable tool to explore and reveal the internal organization of nodes. However, only a few methods were directly designed for community-detection in directed networks. In this article, we introduce the concept of local community structure in directed networks and provide a generic criterion to describe a local community with two properties. We further propose a stochastic optimization algorithm to rapidly detect a local community, which allows for uncovering the directional modular characteristics in directed networks. Numerical results show that the proposed method can resolve detailed local communities with directional information and provide more structural characteristics of directed networks than previous methods.

  17. FUEL ASSEMBLY SHAKER TEST SIMULATION

    SciTech Connect (OSTI)

    Klymyshyn, Nicholas A.; Sanborn, Scott E.; Adkins, Harold E.; Hanson, Brady D.

    2013-05-30

    This report describes the modeling of a PWR fuel assembly under dynamic shock loading in support of the Sandia National Laboratories (SNL) shaker test campaign. The focus of the test campaign is on evaluating the response of used fuel to shock and vibration loads that a can occur during highway transport. Modeling began in 2012 using an LS-DYNA fuel assembly model that was first created for modeling impact scenarios. SNL’s proposed test scenario was simulated through analysis and the calculated results helped guide the instrumentation and other aspects of the testing. During FY 2013, the fuel assembly model was refined to better represent the test surrogate. Analysis of the proposed loads suggested the frequency band needed to be lowered to attempt to excite the lower natural frequencies of the fuel assembly. Despite SNL’s expansion of lower frequency components in their five shock realizations, pretest predictions suggested a very mild dynamic response to the test loading. After testing was completed, one specific shock case was modeled, using recorded accelerometer data to excite the model. Direct comparison of predicted strain in the cladding was made to the recorded strain gauge data. The magnitude of both sets of strain (calculated and recorded) are very low, compared to the expected yield strength of the Zircaloy-4 material. The model was accurate enough to predict that no yielding of the cladding was expected, but its precision at predicting micro strains is questionable. The SNL test data offers some opportunity for validation of the finite element model, but the specific loading conditions of the testing only excite the fuel assembly to respond in a limited manner. For example, the test accelerations were not strong enough to substantially drive the fuel assembly out of contact with the basket. Under this test scenario, the fuel assembly model does a reasonable job of approximating actual fuel assembly response, a claim that can be verified through direct comparison of model results to recorded test results. This does not offer validation for the fuel assembly model in all conceivable cases, such as high kinetic energy shock cases where the fuel assembly might lift off the basket floor to strike to basket ceiling. This type of nonlinear behavior was not witnessed in testing, so the model does not have test data to be validated against.a basis for validation in cases that substantially alter the fuel assembly response range. This leads to a gap in knowledge that is identified through this modeling study. The SNL shaker testing loaded a surrogate fuel assembly with a certain set of artificially-generated time histories. One thing all the shock cases had in common was an elimination of low frequency components, which reduces the rigid body dynamic response of the system. It is not known if the SNL test cases effectively bound all highway transportation scenarios, or if significantly greater rigid body motion than was tested is credible. This knowledge gap could be filled through modeling the vehicle dynamics of a used fuel conveyance, or by collecting acceleration time history data from an actual conveyance under highway conditions.

  18. Projective simulation for artificial intelligence

    E-Print Network [OSTI]

    Hans J. Briegel; Gemma De las Cuevas

    2013-02-08

    We propose a model of a learning agent whose interaction with the environment is governed by a simulation-based projection, which allows the agent to project itself into future situations before it takes real action. Projective simulation is based on a random walk through a network of clips, which are elementary patches of episodic memory. The network of clips changes dynamically, both due to new perceptual input and due to certain compositional principles of the simulation process. During simulation, the clips are screened for specific features which trigger factual action of the agent. The scheme is different from other, computational, notions of simulation, and it provides a new element in an embodied cognitive science approach to intelligent action and learning. Our model provides a natural route for generalization to quantum-mechanical operation and connects the fields of reinforcement learning and quantum computation.

  19. Massive Parallel Quantum Computer Simulator

    E-Print Network [OSTI]

    K. De Raedt; K. Michielsen; H. De Raedt; B. Trieu; G. Arnold; M. Richter; Th. Lippert; H. Watanabe; N. Ito

    2006-08-30

    We describe portable software to simulate universal quantum computers on massive parallel computers. We illustrate the use of the simulation software by running various quantum algorithms on different computer architectures, such as a IBM BlueGene/L, a IBM Regatta p690+, a Hitachi SR11000/J1, a Cray X1E, a SGI Altix 3700 and clusters of PCs running Windows XP. We study the performance of the software by simulating quantum computers containing up to 36 qubits, using up to 4096 processors and up to 1 TB of memory. Our results demonstrate that the simulator exhibits nearly ideal scaling as a function of the number of processors and suggest that the simulation software described in this paper may also serve as benchmark for testing high-end parallel computers.

  20. Multilevel Monte Carlo simulation of Coulomb collisions

    SciTech Connect (OSTI)

    Rosin, M.S.; Ricketson, L.F.; Dimits, A.M.; Caflisch, R.E.; Cohen, B.I.

    2014-10-01

    We present a new, for plasma physics, highly efficient multilevel Monte Carlo numerical method for simulating Coulomb collisions. The method separates and optimally minimizes the finite-timestep and finite-sampling errors inherent in the Langevin representation of the Landau–Fokker–Planck equation. It does so by combining multiple solutions to the underlying equations with varying numbers of timesteps. For a desired level of accuracy ?, the computational cost of the method is O(?{sup ?2}) or O(?{sup ?2}(ln?){sup 2}), depending on the underlying discretization, Milstein or Euler–Maruyama respectively. This is to be contrasted with a cost of O(?{sup ?3}) for direct simulation Monte Carlo or binary collision methods. We successfully demonstrate the method with a classic beam diffusion test case in 2D, making use of the Lévy area approximation for the correlated Milstein cross terms, and generating a computational saving of a factor of 100 for ?=10{sup ?5}. We discuss the importance of the method for problems in which collisions constitute the computational rate limiting step, and its limitations.

  1. Neoclassical simulations of fusion alpha particles in pellet charge exchange experiments on the Tokamak Fusion Test Reactor

    E-Print Network [OSTI]

    1 Neoclassical simulations of fusion alpha particles in pellet charge exchange experiments an estimate of the actual alpha particle densities measured with the pellet charge exchange diagnostic. PACS in TFTR. These simulations are compared to profiles directly measured with the pellet charge exchange

  2. Neoclassical simulations of fusion alpha particles in pellet charge exchange experiments on the Tokamak Fusion Test Reactor

    E-Print Network [OSTI]

    Redi, Martha H.

    1 Neoclassical simulations of fusion alpha particles in pellet charge exchange experiments with the pellet charge exchange diagnostic. PACS: 52.25.Fi, 52.55.Fa, 52.55.Pi, 52.65.-y a redi@princeton.edu b. These simulations are compared to profiles directly measured with the pellet charge exchange diagnostic (PCX) [4, 5

  3. Sub-mm Galaxies in Cosmological Simulations

    E-Print Network [OSTI]

    Mark A. Fardal; Neal Katz; David H. Weinberg; Romeel Davé; Lars Hernquist

    2001-07-16

    We study the predicted sub-mm emission from massive galaxies in a Lambda-CDM universe, using hydrodynamic cosmological simulations. Assuming that most of the emission from newly formed stars is absorbed and reradiated in the rest-frame far-IR, we calculate the number of galaxies that would be detected in sub-mm surveys conducted with SCUBA. The predicted number counts are strongly dependent on the assumed dust temperature and emissivity law. With plausible choices for SED parameters (e.g., T=35 K, beta=1.0), the simulation predictions reproduce the observed number counts above ~ 1 mJy. The sources have a broad redshift distribution with median z ~ 2, in reasonable agreement with observational constraints. However, the predicted count distribution may be too steep at the faint end, and the fraction of low redshift objects may be larger than observed. In this physical model of the sub-mm galaxy population, the objects detected in existing surveys consist mainly of massive galaxies (several M_*) forming stars fairly steadily over timescales ~ 10^8-10^9 years, at moderate rates ~100 Msun/yr. The typical descendants of these sub-mm sources are even more massive galaxies, with old stellar populations, found primarily in dense environments. While the resolution of our simulations is not sufficient to determine galaxy morphologies, these properties support the proposed identification of sub-mm sources with massive ellipticals in the process of formation. The most robust and distinctive prediction of this model, stemming directly from the long timescale and correspondingly moderate rate of star formation, is that the far-IR SEDs of SCUBA sources have a relative high 850 micron luminosity for a given bolometric luminosity. [Abridged

  4. DIRECT LIQUEFACTION PROOF OF CONCEPT

    SciTech Connect (OSTI)

    1998-09-01

    The eighth bench scale test of POC program, Run PB-08, was successfully completed from August 8 to August 26, 1997. A total of five operating conditions were tested aiming at evaluating the reactivity of different pyrolysis oils in liquefaction of a Wyoming sub-bituminous coal (Black Thunder coal). For the first time, water soluble promoters were incorporated into the iron-based GelCat to improve the dispersion of the promoter metals in the feed blend. The concentration of the active metals, Mo and Fe, was 100 and 1000 ppm of moisture-free coal, respectively. Black Thunder coal used in this run was the same batch as tested in HTI?s Run POC-02. Similar to Runs PB-01 through 7, this run employed two back mixed slurry reactors, an interstage gas/slurry separator and a direct-coupled hydrotreater. In addition to the hot vapor from the second stage separator, the first stage separator overhead liquid was also fed to the hydrotreater, which was packed with Criterion C-411 hydrotreating catalyst. Pyrolysis oil was produced off-line from a pyrolysis unit acquired from University of Wyoming. Solids rejection was achieved by purging out pressure filter solid. The recycle solvents consisted of O-6 separator bottoms and pressure filter liquid (PFL). The Run PB-08 proceeded very smoothly without any interruptions. Coal conversion consistently above 90W% was achieved. High resid conversion and distillate yield have been obtained from co-processing of coal and 343°C+ (650°F+) pyrolysis oil. Light gas (C1-C3 ) yield was minimized and hydrogen consumption was reduced due to the introduction of pyrolysis oil, compared with conventional coal-derived solvent. Catalytic activity was improved by incorporating a promoter metal into the iron-based GelCat. It seemed that lowering the first stage temperature to 435°C might increase the hydrogenation function of the promoter metal. In comparison with previous coal-waste coprocessing run (PB-06), significant improvements in the process performance were achieved due to catalyst modification and integration of pyrolysis technique into liquefaction.

  5. Linking atomistic and mesoscale simulations of nanocrystalline materials : quantitative validation for the case of grain growth.

    SciTech Connect (OSTI)

    Moldovan, D.; Wolf, D.; Phillpot, S. R.; Materials Science Division; Louisiana State Univ.

    2003-11-01

    Using grain growth in nanocrystalline palladium as a simple case study, we demonstrate how a novel mesoscale approach for simulating microstructural evolution in polycrystalline materials can be validated directly against atomic-level simulations of the same system. We first describe molecular dynamics simulations of grain growth in a columnar model microstructure. The atomic-level insights into the grain-growth mechanism gained from these simulations, particularly in the role of grain rotations, are captured theoretically for incorporation into the mesoscale approach, in which the objects evolving in space and time are the grain boundaries and grain junctions rather than the atoms. With all the input parameters to the mesoscale being physically well defined and obtained directly from the atomic-level simulations, the mesoscale simulations are fully prescribed. We find that the morphology of the mesoscale system evolves in an almost identical manner with that of the molecular dynamics simulation, demonstrating that the length- and time-scale linking has been performed correctly. When applied to systems containing large numbers of grains, the now validated mesoscale simulation approach allows the growth topology and long-time growth kinetics to be determined. As an outlook, we describe how the effects of applied stress can be incorporated.

  6. Pore-scale lattice Boltzmann simulation of laminar and turbulent flow through a sphere pack

    E-Print Network [OSTI]

    Fattahia, Ehsan; Wohlmuth, Barbara; Rüde, Ulrich; Manhart, Michael; Helmig, Rainer

    2015-01-01

    The lattice Boltzmann method can be used to simulate flow through porous media with full geometrical resolution. With such a direct numerical simulation, it becomes possible to study fundamental effects which are difficult to assess either by developing macroscopic mathematical models or experiments. We first evaluate the lattice Boltzmann method with various boundary handling of the solid-wall and various collision operators to assess their suitability for large scale direct numerical simulation of porous media flow. A periodic pressure drop boundary condition is used to mimic the pressure driven flow through the simple sphere pack in a periodic domain. The evaluation of the method is done in the Darcy regime and the results are compared to a semi-analytic solution. Taking into account computational cost and accuracy, we choose the most efficient combination of the solid boundary condition and collision operator. We apply this method to perform simulations for a wide range of Reynolds numbers from Stokes flo...

  7. Directional detection of dark matter streams

    E-Print Network [OSTI]

    Ciaran A. J. O'Hare; Anne M. Green

    2014-11-11

    Directional detection of WIMPs, in which the energies and directions of the recoiling nuclei are measured, currently presents the only prospect for probing the local velocity distribution of Galactic dark matter. We investigate the extent to which future directional detectors would be capable of probing dark matter substructure in the form of streams. We analyse the signal expected from a Sagittarius-like stream and also explore the full parameter space of stream speed, direction, dispersion and density. Using a combination of non-parametric directional statistics, a profile likelihood ratio test and Bayesian parameter inference we find that within acceptable exposure times (O(10) kg yr for cross sections just below the current exclusion limits) future directional detectors will be sensitive to a wide range of stream velocities and densities. We also examine and discuss the importance of the energy window of the detector.

  8. The Xygra gun simulation tool.

    SciTech Connect (OSTI)

    Garasi, Christopher Joseph; Lamppa, Derek C.; Aubuchon, Matthew S.; Shirley, David Noyes; Robinson, Allen Conrad; Russo, Thomas V.

    2008-12-01

    Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.

  9. Simulations with dynamical HISQ quarks

    E-Print Network [OSTI]

    A. Bazavov; C. Bernard; C. DeTar; W. Freeman; Steven Gottlieb; U. M. Heller; J. E. Hetrick; J. Laiho; L. Levkova; M. Oktay; J. Osborn; R. L. Sugar; D. Toussaint; R. S. Van de Water

    2010-12-06

    We report on the status of a program of generating and using configurations with four flavors of dynamical quarks, using the HISQ action. We study the lattice spacing dependence of physical quantities in these simulations, using runs at several lattice spacings, but with the light quark mass held fixed at two tenths of the strange quark mass. We find that the lattice artifacts in the HISQ simulations are much smaller than those in the asqtad simulations at the same lattice spacings and quark masses. We also discuss methods for setting the scale, or assigning a lattice spacing to ensembles run at unphysical parameters.

  10. Numerical wind speed simulation model

    SciTech Connect (OSTI)

    Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.

    1981-09-01

    A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.

  11. Air breathing direct methanol fuel cell

    DOE Patents [OSTI]

    Ren, Xiaoming (Los Alamos, NM); Gottesfeld, Shimshon (Los Alamos, NM)

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  12. Direct conversion of algal biomass to biofuel

    DOE Patents [OSTI]

    Deng, Shuguang; Patil, Prafulla D; Gude, Veera Gnaneswar

    2014-10-14

    A method and system for providing direct conversion of algal biomass. Optionally, the method and system can be used to directly convert dry algal biomass to biodiesels under microwave irradiation by combining the reaction and combining steps. Alternatively, wet algae can be directly processed and converted to fatty acid methyl esters, which have the major components of biodiesels, by reacting with methanol at predetermined pressure and temperature ranges.

  13. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirectDirectDirect

  14. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    quantities. Because Criegee intermediates have long been thought to play a key role in atmospheric chemistry, the announcement of a method to directly measure their reactivity...

  15. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Direct Kinetic Measurements of a Criegee Intermediate Print In the earth's troposphere, which blankets the planet surface where we live and breathe, dust particles, gas molecules,...

  16. Geothermal Direct Use Technology and the Marketplace

    Broader source: Energy.gov [DOE]

    Geothermal energy applications are emerging across a much wider spectrum of cascaded uses, from lower temperature geothermal energy production to direct heating and cooling, to agricultural uses.

  17. Direct-Cooled Power Electronic Substrate

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    70C standalone cooling loop * Three dimensional inverter packaging and eliminating the heat exchanger volume by directly cooling the DBC result in compact, light weight design...

  18. Optically Directed Assembly of Continuous Mesoscale Filaments...

    Office of Scientific and Technical Information (OSTI)

    Optically Directed Assembly of Continuous Mesoscale Filaments Bahns, J. T.; Sankaranarayanan, S. K. R. S.; Gray, S. K.; Chen, L. Not Available American Physical Society None USDOE...

  19. Ionization based multi-directional flow sensor

    DOE Patents [OSTI]

    Chorpening, Benjamin T. (Morgantown, WV); Casleton, Kent H. (Morgantown, WV)

    2009-04-28

    A method, system, and apparatus for conducting real-time monitoring of flow (airflow for example) in a system (a hybrid power generation system for example) is disclosed. The method, system and apparatus measure at least flow direction and velocity with minimal pressure drop and fast response. The apparatus comprises an ion source and a multi-directional collection device proximate the ion source. The ion source is configured to generate charged species (electrons and ions for example). The multi-directional collection source is configured to determine the direction and velocity of the flow in real-time.

  20. Future Directions in Spatial Demography, Final Report

    E-Print Network [OSTI]

    Matthews, Stephen A.; Janelle, Donald G.; Goodchild, Michael F.

    2012-01-01

    the meeting’s final reception. Future Directions in SpatialH. (2007) Five Minds for the Future. Cambridge, MA: Harvardhorizons, envisioning the future. Social Science and

  1. High Temperature 300°C Directional Drilling System

    Broader source: Energy.gov [DOE]

    Project objective: provide a directional drilling system that can be used at environmental temperatures of up to 300°C; and at depths of 10; 000 meters.

  2. One Direction: Researchers grow nanocircuitry with semiconducting...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    partners@anl.gov. One Direction: Researchers grow nanocircuitry with semiconducting graphene nanoribbons By Justin H.S. Breaux * October 13, 2015 Tweet EmailPrint In a...

  3. Heat Recovery Steam Generator Simulation 

    E-Print Network [OSTI]

    Ganapathy, V.

    1993-01-01

    The paper discusses the applications of Heat Recovery Steam Generator Simulation. Consultants, plant engineers and plant developers can evaluate the steam side performance of HRSGs and arrive at the optimum system which matches the needs...

  4. Parallel Simulation for VLSI Power Grid 

    E-Print Network [OSTI]

    Zhang, Le

    2015-07-23

    Due to the increasing complexity of VLSI circuits, power grid simulation has become more and more time-consuming. Hence, there is a need for fast and accurate power grid simulator. In order to perform power grid simulation ...

  5. Modeling and simulation technology readiness levels.

    SciTech Connect (OSTI)

    Clay, Robert L.; Shneider, Max S.; Marburger, S. J.; Trucano, Timothy Guy

    2006-01-01

    This report summarizes the results of an effort to establish a framework for assigning and communicating technology readiness levels (TRLs) for the modeling and simulation (ModSim) capabilities at Sandia National Laboratories. This effort was undertaken as a special assignment for the Weapon Simulation and Computing (WSC) program office led by Art Hale, and lasted from January to September 2006. This report summarizes the results, conclusions, and recommendations, and is intended to help guide the program office in their decisions about the future direction of this work. The work was broken out into several distinct phases, starting with establishing the scope and definition of the assignment. These are characterized in a set of key assertions provided in the body of this report. Fundamentally, the assignment involved establishing an intellectual framework for TRL assignments to Sandia's modeling and simulation capabilities, including the development and testing of a process to conduct the assignments. To that end, we proposed a methodology for both assigning and understanding the TRLs, and outlined some of the restrictions that need to be placed on this process and the expected use of the result. One of the first assumptions we overturned was the notion of a ''static'' TRL--rather we concluded that problem context was essential in any TRL assignment, and that leads to dynamic results (i.e., a ModSim tool's readiness level depends on how it is used, and by whom). While we leveraged the classic TRL results from NASA, DoD, and Sandia's NW program, we came up with a substantially revised version of the TRL definitions, maintaining consistency with the classic level definitions and the Predictive Capability Maturity Model (PCMM) approach. In fact, we substantially leveraged the foundation the PCMM team provided, and augmented that as needed. Given the modeling and simulation TRL definitions and our proposed assignment methodology, we conducted four ''field trials'' to examine how this would work in practice. The results varied substantially, but did indicate that establishing the capability dependencies and making the TRL assignments was manageable and not particularly time consuming. The key differences arose in perceptions of how this information might be used, and what value it would have (opinions ranged from negative to positive value). The use cases and field trial results are included in this report. Taken together, the results suggest that we can make reasonably reliable TRL assignments, but that using those without the context of the information that led to those results (i.e., examining the measures suggested by the PCMM table, and extended for ModSim TRL purposes) produces an oversimplified result--that is, you cannot really boil things down to just a scalar value without losing critical information.

  6. Geomechanical modeling of reservoir compaction, surface subsidence, and casing damage at the Belridge diatomite field

    SciTech Connect (OSTI)

    FREDRICH,JOANNE T.; DEITRICK,G.L.; ARGUELLO JR.,JOSE G.; DEROUFFIGNAC,E.P.

    2000-05-01

    Geologic, and historical well failure, production, and injection data were analyzed to guide development of three-dimensional geomechanical models of the Belridge diatomite field, California. The central premise of the numerical simulations is that spatial gradients in pore pressure induced by production and injection in a low permeability reservoir may perturb the local stresses and cause subsurface deformation sufficient to result in well failure. Time-dependent reservoir pressure fields that were calculated from three-dimensional black oil reservoir simulations were coupled uni-directionally to three-dimensional non-linear finite element geomechanical simulations. The reservoir models included nearly 100,000 gridblocks (100--200 wells), and covered nearly 20 years of production and injection. The geomechanical models were meshed from structure maps and contained more than 300,000 nodal points. Shear strain localization along weak bedding planes that causes casing dog-legs in the field was accommodated in the model by contact surfaces located immediately above the reservoir and at two locations in the overburden. The geomechanical simulations are validated by comparison of the predicted surface subsidence with field measurements, and by comparison of predicted deformation with observed casing damage. Additionally, simulations performed for two independently developed areas at South Belridge, Sections 33 and 29, corroborate their different well failure histories. The simulations suggest the three types of casing damage observed, and show that although water injection has mitigated surface subsidence, it can, under some circumstances, increase the lateral gradients in effective stress, that in turn can accelerate subsurface horizontal motions. Geomechanical simulation is an important reservoir management tool that can be used to identify optimal operating policies to mitigate casing damage for existing field developments, and applied to incorporate the effect of well failure potential in economic analyses of alternative infilling and development options.

  7. Direct Measurement of the Surface Tension of Nanobubbles

    E-Print Network [OSTI]

    Attard, Phil

    2015-01-01

    It is shown that when the nanobubble contact line is pinned to a penetrating tip the interface behaves like a Hookean spring with spring constant proportional to the nanobubble surface tension. Atomic force microscope (AFM) data for several nanobubbles and solutions are analysed and yield surface tensions in the range 0.04--0.05 N/m (compared to 0.072 N/m for saturated water), and supersaturation ratios in the range 2--5. These are the first direct measurements of the surface tension of a supersaturated air-water interface. The results are consistent with recent theories of nanobubble size and stability, and with computer simulations of the surface tension of a supersaturated solution.

  8. Direct Measurement of the Surface Tension of Nanobubbles

    E-Print Network [OSTI]

    Phil Attard

    2015-05-09

    It is shown that when the nanobubble contact line is pinned to a penetrating tip the interface behaves like a Hookean spring with spring constant proportional to the nanobubble surface tension. Atomic force microscope (AFM) data for several nanobubbles and solutions are analysed and yield surface tensions in the range 0.04--0.05 N/m (compared to 0.072 N/m for saturated water), and supersaturation ratios in the range 2--5. These are the first direct measurements of the surface tension of a supersaturated air-water interface. The results are consistent with recent theories of nanobubble size and stability, and with computer simulations of the surface tension of a supersaturated solution.

  9. Optimization of Direct Ionization of CO2 by Controlling the Gas Flow Inside of a Beam-Target

    SciTech Connect (OSTI)

    Salazar Quintero, G A; Ognibene, T

    2011-03-07

    We designed and optimized a target that directs a CO{sub 2} pulse onto a Ti surface where a Cs{sup +} sputtering beam ionizes the CO{sub 2} to generate C{sup -}. These targets will be used for the direct ionization of CO{sub 2} pulses to enable the measurement of carbon isotope ratios in real time. The design was based on the results of Comsol{trademark} simulations of the target configurations.

  10. Understanding WIMP-baryon interactions with direct detection: A Roadmap

    E-Print Network [OSTI]

    Vera Gluscevic; Annika H. G. Peter

    2014-06-30

    We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.

  11. Understanding WIMP-baryon interactions with direct detection: a roadmap

    SciTech Connect (OSTI)

    Gluscevic, Vera; Peter, Annika H.G. E-mail: apeter@physics.osu.edu

    2014-09-01

    We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.

  12. Sub-femtosecond electron bunches created by direct laser acceleration in a laser wakefield accelerator with ionization injection

    E-Print Network [OSTI]

    Lemos, N; Marsh, K A; Joshi, C

    2015-01-01

    In this work, we will show through three-dimensional particle-in-cell simulations that direct laser acceleration in laser a wakefield accelerator can generate sub-femtosecond electron bunches. Two simulations were done with two laser pulse durations, such that the shortest laser pulse occupies only a fraction of the first bubble, whereas the longer pulse fills the entire first bubble. In the latter case, as the trapped electrons moved forward and interacted with the high intensity region of the laser pulse, micro-bunching occurred naturally, producing 0.5 fs electron bunches. This is not observed in the short pulse simulation.

  13. Thermal Simulation of Advanced Powertrain Systems | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Simulation of Advanced Powertrain Systems Thermal Simulation of Advanced Powertrain Systems Under this project, the Volvo complete vehicle model was modified to include engine and...

  14. Clot Busting Simulations Test Potential Stroke Treatment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Clot Busting Simulations Test Potential Stroke Treatment Clot Busting Simulations Test Potential Stroke Treatment September 24, 2013 | Tags: Biological and Environmental Research...

  15. Vehicle Modeling and Simulation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Modeling and Simulation Vehicle Modeling and Simulation Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008 in Bethesda,...

  16. Mesoscale Simulations of Coarsening in GB Networks

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mukul Kumar is the Principal Investigator for Mesoscale Simulations of Coarsening in GB Networks LLNL BES Programs Highlight Mesoscale Simulations of Coarsening in GB Networks The...

  17. Theory, Modeling & Simulation | More Science | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Materials Theory and Simulation SHARE Materials Theory and Simulation ORNL conducts a broad range of theoretical research in the physical sciences with over 60 staff members and...

  18. Theory, Modeling & Simulation | More Science | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Theory, Modeling and Simulation SHARE Theory, Modeling and Simulation ORNL conducts a broad range of theoretical research in the physical sciences with over 60 staff members and...

  19. Advanced simulation capability for environmental management ...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Advanced simulation capability for environmental management (ASCEM): An overview of initial results Citation Details In-Document Search Title: Advanced simulation...

  20. Advanced Simulation Capability for Environmental Management ...

    Office of Scientific and Technical Information (OSTI)

    Advanced Simulation Capability for Environmental Management (ASCEM): Early Site Demonstration Citation Details In-Document Search Title: Advanced Simulation Capability for...

  1. of Flow on Morphological Stability Directional Solidification

    E-Print Network [OSTI]

    Schulze, Tim

    Effects During of Flow on Morphological Stability Directional Solidification S.H. DAVIS and T.P. SCHULZE Research involving the interaction of flow with morphological instability during directional solidifi- cation of binary alloys is reviewed. In general, flow may arise during the solidification process

  2. Direct mechanism in solar nuclear reactions

    E-Print Network [OSTI]

    H. Oberhummer; G. Staudt

    1994-04-22

    A short overview of the direct reaction mechanism and the models used for the analysis of such processes is given. Nuclear reactions proceeding through the direct mechanism and involved in solar hydrogen burning are discussed. The significance of these nuclear reactions with respect to the solar neutrino problem is investigated.

  3. DIRECT ADAPTIVE CONTROL OF RESIN TRANSFER MOLDING

    E-Print Network [OSTI]

    Mamishev, Alexander

    of defects, control of mold filling is needed. In this paper, direct adaptive control strategy is presented is a crucial stage in RTM. Defect-free parts cannot be obtained without successful consistent mold fillingDIRECT ADAPTIVE CONTROL OF RESIN TRANSFER MOLDING B. Minaie1,* , W. Li, J. Gou1 , Y. Chen2 , A

  4. DIRECTING THE MOVEMENT OF FISH WITH ELECTRICITY

    E-Print Network [OSTI]

    DIRECTING THE MOVEMENT OF FISH WITH ELECTRICITY Marine Biological Laboratory APR 21 1953 WOODS HOLE, Albert M. Day, Director DIRECTING THE MOVH-IENT OF FISH WITH ELECTRICITY by Alberton L. McLain Fishery of an electrical leading device 21 Literature cited. ..,...,..,..........·· 2k ILLUSTRATIONS Figure Page 1. Diagram

  5. MANUFACTURING LOGISTICS RESEARCH: TAXONOMY AND DIRECTIONS

    E-Print Network [OSTI]

    Wu, David

    MANUFACTURING LOGISTICS RESEARCH: TAXONOMY AND DIRECTIONS S. DAVID WU Lehigh University, Bethlehem research directions and opportunities in manufacturing logistics based on recommendations from an NSF in manufacturing logistics by the physical entities (systems) involved, the level-of-abstraction, the focus

  6. Exceptional ion rejection ability of directional solvent for non-membrane desalination

    SciTech Connect (OSTI)

    Rish, Daniel [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Civil Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Luo, Shirui; Kurtz, Brien [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Luo, Tengfei, E-mail: tluo@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Center for Sustainable Energy at Notre Dame, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2014-01-13

    The recently demonstrated directional solvent extraction (DSE) is promising for very low temperature, membrane-free water desalination. In this paper, we combine atomistic simulations and experimental validation to demonstrate that the currently used directional solvent, decanoic acid, can reject all major salt ions in seawater, with very high rejection rates. The salinities of the DSE recovered water show that ion rejection rates are ?98%–99%—similar to those of the best reverse osmosis membranes. Our test also shows that the DSE process can desalt seawater to produce fresh water that meets drinking water standards.

  7. Directed polymer near a hard wall and KPZ equation in the half-space

    E-Print Network [OSTI]

    Thomas Gueudre; Pierre Le Doussal

    2012-09-17

    We study the directed polymer with fixed endpoints near an absorbing wall, in the continuum and in presence of disorder, equivalent to the KPZ equation on the half space with droplet initial conditions. From a Bethe Ansatz solution of the equivalent attractive boson model we obtain the exact expression for the free energy distribution at all times. It converges at large time to the Tracy Widom distribution $F_4$ of the Gaussian Symplectic Ensemble (GSE). We compare our results with numerical simulations of the lattice directed polymer, both at zero and high temperature.

  8. Understanding WIMP-baryon interactions with direct detection: A Roadmap

    E-Print Network [OSTI]

    Gluscevic, Vera

    2014-01-01

    We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to s...

  9. 2D numerical simulation of the MEP energy-transport model with a finite difference scheme

    SciTech Connect (OSTI)

    Romano, V. . E-mail: romano@dmi.unict.it

    2007-02-10

    A finite difference scheme of Scharfetter-Gummel type is used to simulate a consistent energy-transport model for electron transport in semiconductors devices, free of any fitting parameters, formulated on the basis of the maximum entropy principle. Simulations of silicon n{sup +}-n-n{sup +} diodes, 2D-MESFET and 2D-MOSFET and comparisons with the results obtained by a direct simulation of the Boltzmann transport equation and with other energy-transport models, known in the literature, show the validity of the model and the robustness of the numerical scheme.

  10. Can One Trust Quantum Simulators?

    E-Print Network [OSTI]

    Philipp Hauke; Fernando M. Cucchietti; Luca Tagliacozzo; Ivan Deutsch; Maciej Lewenstein

    2012-07-26

    Various fundamental phenomena of strongly-correlated quantum systems such as high-$T_c$ superconductivity, the fractional quantum-Hall effect, and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models that are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper [Int. J. Theor. Phys. 21, 467], Richard Feynman suggested that such models might be solved by "simulation" with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a "quantum simulator," would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability, and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question "Can we trust quantum simulators?" is... to some extent.

  11. Three-dimensional multiscale modeling of dendritic spacing selection during Al-Si directional solidification

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tourret, Damien; Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Gibbs, John W.; Karma, Alain

    2015-05-27

    We present a three-dimensional extension of the multiscale dendritic needle network (DNN) model. This approach enables quantitative simulations of the unsteady dynamics of complex hierarchical networks in spatially extended dendritic arrays. We apply the model to directional solidification of Al-9.8 wt.%Si alloy and directly compare the model predictions with measurements from experiments with in situ x-ray imaging. The focus is on the dynamical selection of primary spacings over a range of growth velocities, and the influence of sample geometry on the selection of spacings. Simulation results show good agreement with experiments. The computationally efficient DNN model opens new avenues formore »investigating the dynamics of large dendritic arrays at scales relevant to solidification experiments and processes.« less

  12. Contrasting the direct radiative effect and direct radiative forcing of aerosols

    E-Print Network [OSTI]

    Heald, Colette L.

    The direct radiative effect (DRE) of aerosols, which is the instantaneous radiative impact of all atmospheric particles on the Earth's energy balance, is sometimes confused with the direct radiative forcing (DRF), which ...

  13. Progress in direct-drive inertial confinement fusion

    SciTech Connect (OSTI)

    McCrory, R. L.; Meyerhofer, D. D.; Betti, R.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Jacobs-Perkins, D. W.; Knauer, J. P.; Marshall, F. J.; McKenty, P. W.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Seka, W.; Short, R. W.; Skupsky, S.; Smalyuk, V. A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)] (and others)

    2008-05-15

    Significant progress in direct-drive inertial confinement fusion (ICF) research has been made since the completion of the 60-beam, 30-kJ{sub UV} OMEGA Laser System [Boehly, Opt. Commun. 133, 495 (1997)] in 1995. A theory of ignition requirements, applicable to any ICF concept, has been developed. Detailed understanding of laser-plasma coupling, electron thermal transport, and hot-electron preheating has lead to the measurement of neutron-averaged areal densities of {approx}200 mg/cm{sup 2} in cryogenic target implosions. These correspond to an estimated peak fuel density in excess of 100 g/cm{sup 3} and are in good agreement with hydrodynamic simulations. The implosions were performed using an 18-kJ drive pulse designed to put the converging fuel on an adiabat of two. The polar-drive concept will allow direct-drive-ignition research on the National Ignition Facility while it is configured for indirect drive. Advanced ICF ignition concepts - fast ignition [Tabak et al., Phys. Plasmas 1, 1626 (1994)] and shock ignition [Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] - have the potential to significantly reduce ignition driver energies and/or provide higher target gain.

  14. LFSC - Linac Feedback Simulation Code

    SciTech Connect (OSTI)

    Ivanov, Valentin; /Fermilab

    2008-05-01

    The computer program LFSC (Simulation Code>) is a numerical tool for simulation beam based feedback in high performance linacs. The code LFSC is based on the earlier version developed by a collective of authors at SLAC (L.Hendrickson, R. McEwen, T. Himel, H. Shoaee, S. Shah, P. Emma, P. Schultz) during 1990-2005. That code was successively used in simulation of SLC, TESLA, CLIC and NLC projects. It can simulate as pulse-to-pulse feedback on timescale corresponding to 5-100 Hz, as slower feedbacks, operating in the 0.1-1 Hz range in the Main Linac and Beam Delivery System. The code LFSC is running under Matlab for MS Windows operating system. It contains about 30,000 lines of source code in more than 260 subroutines. The code uses the LIAR ('Linear Accelerator Research code') for particle tracking under ground motion and technical noise perturbations. It uses the Guinea Pig code to simulate the luminosity performance. A set of input files includes the lattice description (XSIF format), and plane text files with numerical parameters, wake fields, ground motion data etc. The Matlab environment provides a flexible system for graphical output.

  15. ATLAS Fast Tracker Simulation Challenges

    E-Print Network [OSTI]

    Adelman, Jahred; The ATLAS collaboration; Borodin, Mikhail; Chakraborty, Dhiman; García Navarro, José Enrique; Golubkov, Dmitry; Kama, Sami; Panitkin, Sergey; Smirnov, Yuri; Stewart, Graeme; Tompkins, Lauren; Vaniachine, Alexandre; Volpi, Guido

    2015-01-01

    To deal with Big Data flood from the ATLAS detector most events have to be rejected in the trigger system. the trigger rejection is complicated by the presence of a large number of minimum-bias events – the pileup. To limit pileup effects in the high luminosity environment of the LHC Run-2, ATLAS relies on full tracking provided by the Fast TracKer (FTK) implemented with custom electronics. The FTK data processing pipeline has to be simulated in preparation for LHC upgrades to support electronics design and develop trigger strategies at high luminosity. The simulation of the FTK - a highly parallelized system - has inherent performance bottlenecks on general-purpose CPUs. To take advantage of the Grid Computing power, the FTK simulation is integrated with Monte Carlo simulations at the Production System level above the ATLAS workload management system PanDA. We report on ATLAS experience with FTK simulations on the Grid and next steps for accommodating the growing requirements for resources during the LHC R...

  16. Dehumidification Enhancement of Direct Expansion Systems Through Component Augmentation of the Cooling Coil 

    E-Print Network [OSTI]

    Kosar, D.; Swami, M.; Shirey, D.; Raustad, R.; Basarkar, M.

    2006-01-01

    performance spreadsheet models for single path, mixed air packaged systems compare a conventional “off the shelf” direct expansion (DX) cooling system and its performance to systems that augment the DX coil with enhanced dehumidification components... spreadsheet models combine available algorithms from the EnergyPlus TM simulation program for DX coils and heat exchangers with newly developed algorithms for desiccant dehumidifiers. All the models and their algorithms are applied in EnergyPlus TM...

  17. A robotic crawler exploiting directional frictional interactions: experiments, numerics, and derivation of a reduced model

    E-Print Network [OSTI]

    Giovanni Noselli; Antonio DeSimone

    2014-08-26

    We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. 'breathing-like' deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.

  18. Prediction of internal temperature swings in direct-gain passive-solar buildings

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1983-01-01

    The diurnal heat capacity method is presented for estimating inside-temperature swings attributable to direct winter solar gain. The procedures are simplified to be suitable for hand analysis, aided by tables of diurnal heat capacity for various materials. The method has been spot checked against computer simulation and has been used successfully by a group of 20 builders in New Mexico to analyze whether temperature swings would be excessive in their designs.

  19. Direct Imaging of Asymmetric Magnetization Reversal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirect ImagingDirectDirect

  20. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirect ImagingDirect

  1. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirectDirect Kinetic

  2. Direct Kinetic Measurements of a Criegee Intermediate

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirectDirect

  3. Simulated synchrotron emission from Pulsar Wind Nebulae

    E-Print Network [OSTI]

    Luca Del Zanna; Delia Volpi; Elena Amato; Niccolo' Bucciantini

    2006-03-03

    A complete set of diagnostic tools aimed at producing synthetic synchrotron emissivity, polarization, and spectral index maps from relativistic MHD simulations is presented. As a first application we consider here the case of the emission from Pulsar Wind Nebulae (PWNe). The proposed method is based on the addition, on top of the basic set of MHD equations, of an extra equation describing the evolution of the maximum energy of the emitting particles. This equation takes into account adiabatic and synchrotron losses along streamlines for the distribution of emitting particles and its formulation is such that it is easily implemented in any numerical scheme for relativistic MHD. Application to the axisymmetric simulations of PWNe, analogous to those described by Del Zanna et al. (2004, A&A, 421, 1063), allows direct comparison between the numerical results and observations of the inner structure of the Crab Nebula, and similar objects, in the optical and X-ray bands. We are able to match most of the observed features typical of PWNe, like the equatorial torus and the polar jets, with velocities in the correct range, as well as finer emission details, like arcs, rings and the bright knot, that turn out to arise mainly from Doppler boosting effects. Spectral properties appear to be well reproduced too: detailed spectral index maps are produced for the first time and show softening towards the PWN outer borders, whereas spectral breaks appear in integrated spectra. The emission details are found to strongly depend on both the average wind magnetization (here approximately 2%), and on the magnetic field shape.

  4. Lattice Simulations and Infrared Conformality

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Appelquist, Thomas; Fleming, George T; Lin, Meifeng; Neil, Ethan T; Schaich, David A

    2011-09-01

    We examine several recent lattice-simulation data sets, asking whether they are consistent with infrared conformality. We observe, in particular, that for an SU(3) gauge theory with 12 Dirac fermions in the fundamental representation, recent simulation data can be described assuming infrared conformality. Lattice simulations include a fermion mass m which is then extrapolated to zero, and we note that this data can be fit by a small-m expansion, allowing a controlled extrapolation. We also note that the conformal hypothesis does not work well for two theories that are known or expected to be confining and chirally broken, and that itmore »does work well for another theory expected to be infrared conformal.« less

  5. Simulating chemistry using quantum computers

    E-Print Network [OSTI]

    Ivan Kassal; James D. Whitfield; Alejandro Perdomo-Ortiz; Man-Hong Yung; Alán Aspuru-Guzik

    2010-07-15

    The difficulty of simulating quantum systems, well-known to quantum chemists, prompted the idea of quantum computation. One can avoid the steep scaling associated with the exact simulation of increasingly large quantum systems on conventional computers, by mapping the quantum system to another, more controllable one. In this review, we discuss to what extent the ideas in quantum computation, now a well-established field, have been applied to chemical problems. We describe algorithms that achieve significant advantages for the electronic-structure problem, the simulation of chemical dynamics, protein folding, and other tasks. Although theory is still ahead of experiment, we outline recent advances that have led to the first chemical calculations on small quantum information processors.

  6. Special nuclear material simulation device

    DOE Patents [OSTI]

    Leckey, John H.; DeMint, Amy; Gooch, Jack; Hawk, Todd; Pickett, Chris A.; Blessinger, Chris; York, Robbie L.

    2014-08-12

    An apparatus for simulating special nuclear material is provided. The apparatus typically contains a small quantity of special nuclear material (SNM) in a configuration that simulates a much larger quantity of SNM. Generally the apparatus includes a spherical shell that is formed from an alloy containing a small quantity of highly enriched uranium. Also typically provided is a core of depleted uranium. A spacer, typically aluminum, may be used to separate the depleted uranium from the shell of uranium alloy. A cladding, typically made of titanium, is provided to seal the source. Methods are provided to simulate SNM for testing radiation monitoring portals. Typically the methods use at least one primary SNM spectral line and exclude at least one secondary SNM spectral line.

  7. Simulating Reionization in Numerical Cosmology

    E-Print Network [OSTI]

    Aaron Sokasian; Tom Abel; Lars E. Hernquist

    2001-05-10

    The incorporation of radiative transfer effects into cosmological hydrodynamical simulations is essential for understanding how the intergalactic medium (IGM) makes the transition from a neutral medium to one that is almost fully ionized. Here, we present an approximate numerical method designed to study in a statistical sense how a cosmological density field is ionized by a set of discrete point sources. A diffuse background radiation field is also computed self-consistently in our procedure. The method requires relatively few time steps and can be employed with simulations having high resolution. We describe the details of the algorithm and provide a description of how the method can be applied to the output from a pre-existing cosmological simulation to study the systematic reionization of a particular ionic species. As a first application, we compute the reionization of He II by quasars in the redshift range 3 to 6.

  8. MOOSE: Multiphysics Object-Oriented Simulation Environment

    ScienceCinema (OSTI)

    Gaston, Derek

    2014-05-30

    An overview of Idaho National Laboratory's MOOSE: Multiphysics Object-Oriented Simulation Environment

  9. Integrating software architectures for distributed simulations and simulation analysis communities.

    SciTech Connect (OSTI)

    Goldsby, Michael E.; Fellig, Daniel; Linebarger, John Michael; Moore, Patrick Curtis; Sa, Timothy J.; Hawley, Marilyn F.

    2005-10-01

    The one-year Software Architecture LDRD (No.79819) was a cross-site effort between Sandia California and Sandia New Mexico. The purpose of this research was to further develop and demonstrate integrating software architecture frameworks for distributed simulation and distributed collaboration in the homeland security domain. The integrated frameworks were initially developed through the Weapons of Mass Destruction Decision Analysis Center (WMD-DAC), sited at SNL/CA, and the National Infrastructure Simulation & Analysis Center (NISAC), sited at SNL/NM. The primary deliverable was a demonstration of both a federation of distributed simulations and a federation of distributed collaborative simulation analysis communities in the context of the same integrated scenario, which was the release of smallpox in San Diego, California. To our knowledge this was the first time such a combination of federations under a single scenario has ever been demonstrated. A secondary deliverable was the creation of the standalone GroupMeld{trademark} collaboration client, which uses the GroupMeld{trademark} synchronous collaboration framework. In addition, a small pilot experiment that used both integrating frameworks allowed a greater range of crisis management options to be performed and evaluated than would have been possible without the use of the frameworks.

  10. Sensors and Actuators B 182 (2013) 4552 Contents lists available at SciVerse ScienceDirect

    E-Print Network [OSTI]

    Peter, Yves-Alain

    2013-01-01

    with a simplified analytical model and with finite element simulations. Conventional and phenyl-doped poly to salt [2] hydrocarbons [3] and humidity [4]. Bragg gratings were also fabricated directly with pas- sively aligned conventional single-mode optical fibers, rather than requiring free space

  11. Administration Division Strategic Directions Updated February 2013

    E-Print Network [OSTI]

    Thompson, Michael

    over time within risk tolerances. #12;Administration Division Strategic Directions Updated February of policies and plans. Negotiation of contracts 3.1 Continue top tier labour relations practices 3

  12. Direct transfer of graphene onto flexible substrates

    E-Print Network [OSTI]

    Araujo, Paulo Antonio Trinidade

    In this paper we explore the direct transfer via lamination of chemical vapor deposition graphene onto different flexible substrates. The transfer method investigated here is fast, simple, and does not require an intermediate ...

  13. Reference book on geothermal direct use

    SciTech Connect (OSTI)

    Lienau, P.J.; Lund, J.W.; Rafferty, K.; Culver, G.

    1994-08-01

    This report presents the direct uses of geothermal energy in the United States. Topics discussed include: low-temperature geothermal energy resources; energy reserves; geothermal heat pumps; geothermal energy for residential buildings; and geothermal energy for industrial usage.

  14. Improved Usability of Aviation Automation Through Direct

    E-Print Network [OSTI]

    Kaber, David B.

    Improved Usability of Aviation Automation Through Direct Manipulation and Graphical User Interface Design David B. Kaber and Jennifer M. Riley Department of Industrial Engineering North Carolina State University Kheng-Wooi Tan Department of Industrial Engineering Mississippi State University Problems

  15. Extension of DOE Directives on Security

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2002-05-06

    The Notice extends the following directives until 12/31/02. DOE N 205.1, DOE N 205.2, DOE 205.3, DOE N 471.3, and DOE 473.6.

  16. Geothermal Direct-Use — Minimizing Solid Waste

    Broader source: Energy.gov [DOE]

    Aquaculture and horticulture businesses, and other industries that use geothermal direct-use systems typically don't generate any more solid waste than those that use other energy resources.

  17. Air Breathing Direct Methanol Fuel Cell

    DOE Patents [OSTI]

    Ren; Xiaoming (Los Alamos, NM)

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  18. Future Directions for Federal Research Funding

    E-Print Network [OSTI]

    i Future Directions for Federal Research Funding Merrill Series on The Research Cells: Current Challenges and Future Promise First panel of research administrators Prem Paul and Developmental Disabilities Research Center, University of Kansas Past as Prelude: Lessons for the Future

  19. Geothermal direct use engineering and design guidebook

    SciTech Connect (OSTI)

    Lienau, P.J.; Lunis, B.C.

    1991-01-01

    The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.

  20. Nanoscale Science, Engineering and Technology Research Directions

    E-Print Network [OSTI]

    Wu, Zhigang

    OF CONTENTS Basic Energy Sciences Nanoscience/Nanotechnology Group Basic Energy Sciences Nanoscience/Nanotechnology Group Chair: Douglas H. Lowndes (ORNL) A. Paul#12;#12;Nanoscale Science, Engineering and Technology Research Directions ABSTRACT This report